Overview

Full Name: Allison Taylor Bayliss, also known as Alliy Bayliss

Age at Disappearance: 15 years old

Date of Birth: February 7, 1996

Date Last Seen: May 23, 2011

Last Confirmed School-Area Sighting: San Ramon Valley High School, Danville, California

Hometown: Danville, Contra Costa County, California

Location of Subsequent Investigation: Golden Gate Bridge and surrounding waters, San Francisco Bay Area, California

Case Classification: Missing person; classified as lost/injured missing by The Charley Project. Authorities concluded that Allison apparently died by suicide.

Current Publicly Documented Status: Allison remains listed in the California Department of Justice missing-person database. Her remains have not been publicly confirmed recovered.

Investigating Agency: Contra Costa County Sheriff’s Office, with involvement from Danville police and other agencies during the original search.

Case Overview: On May 23, 2011, 15-year-old Allison “Alliy” Bayliss disappeared after being seen near her high school in Danville. Investigators traced her movements toward San Francisco, where her bicycle was discovered near the Golden Gate Bridge. Evidence led authorities to conclude that she had apparently jumped from the bridge. Despite extensive searching and an outpouring of community support, her remains were not recovered. Her disappearance became a profound loss for her family and community and later inspired efforts to increase awareness of youth depression and suicide prevention.

Detailed Case Breakdown

Case Summary

Full Name: Allison Taylor Bayliss, also known as Alliy Bayliss

Age at Disappearance: 15 years old

Date of Birth: February 7, 1996

Date Last Seen: May 23, 2011

Last Confirmed School-Area Sighting: San Ramon Valley High School, Danville, California

Hometown: Danville, Contra Costa County, California

Location of Subsequent Investigation: Golden Gate Bridge and surrounding waters, San Francisco Bay Area, California

Case Classification: Missing person; classified as lost/injured missing by The Charley Project. Authorities concluded that Allison apparently died by suicide.

Current Publicly Documented Status: Allison remains listed in the California Department of Justice missing-person database. Her remains have not been publicly confirmed recovered.

Investigating Agency: Contra Costa County Sheriff’s Office, with involvement from Danville police and other agencies during the original search.

Case Overview: On May 23, 2011, 15-year-old Allison “Alliy” Bayliss disappeared after being seen near her high school in Danville. Investigators traced her movements toward San Francisco, where her bicycle was discovered near the Golden Gate Bridge. Evidence led authorities to conclude that she had apparently jumped from the bridge. Despite extensive searching and an outpouring of community support, her remains were not recovered. Her disappearance became a profound loss for her family and community and later inspired efforts to increase awareness of youth depression and suicide prevention.

Background and Circumstances of Allison Bayliss’s Disappearance

Allison Taylor Bayliss, affectionately known as “Alliy” to family and friends, was a 15-year-old student living in Danville, California, when she disappeared on May 23, 2011. A sophomore at San Ramon Valley High School, she was remembered as an academically accomplished, compassionate teenager with a wide range of interests and talents.

Allison was an excellent student who participated in competitive swimming and running. She belonged to her school’s junior varsity swim team and enjoyed playing the piano. Friends remembered her musical abilities, including piano performances she shared online. She was also described as thoughtful, generous, and willing to help others.

Those who knew Allison described a young person whose achievements and kindness had made a lasting impression. Following her disappearance, classmates and neighbors spoke publicly about her friendship, determination, and positive influence on the people around her.

Her family later disclosed that Allison had struggled with depression for several years. This information became an important part of the family’s subsequent efforts to raise awareness about adolescent mental health. Her academic and athletic accomplishments did not negate the difficulties she was experiencing privately.

The Morning of May 23, 2011

Allison was last reported seen at approximately 8:00 a.m. on Monday, May 23, 2011, riding her mountain bicycle near San Ramon Valley High School. When she failed to return home later that day, her family became concerned and reported her missing.

Authorities quickly treated the disappearance as an at-risk missing-person case. Contemporary reports indicated that Allison had left a note at home suggesting she might harm herself. Her family and law enforcement therefore recognized that finding her was particularly urgent.

Investigators examined information from Allison’s computer and discovered directions associated with travel from the Dublin BART station toward the Golden Gate Bridge. This finding helped shift the search from the Danville area toward San Francisco.

Authorities subsequently reconstructed a route in which Allison traveled by Bay Area Rapid Transit to San Francisco, exited at the Embarcadero station, and continued by bicycle toward the Golden Gate Bridge.

Discovery of Her Bicycle

On May 24, 2011, Allison’s mountain bicycle was located in the Battery East parking area near the San Francisco end of the Golden Gate Bridge. Reports described the bicycle as secured to a rack, with her helmet left on the handlebars.

The discovery was a significant development because it placed Allison’s belongings close to the bridge and corresponded with the directions investigators had found on her computer.

Her disappearance had initially prompted hopes that she might be found elsewhere in the Bay Area. The evidence near the bridge, however, increasingly directed investigators toward a possible tragedy.

Investigation History and Evidence

The search for Allison Bayliss involved multiple law enforcement agencies, emergency personnel, volunteers, friends, and members of the Danville community. Investigators worked to reconstruct her movements while search teams examined areas around San Francisco and the Golden Gate Bridge.

Initial Search Efforts

Following the missing-person report on May 23, 2011, authorities and community volunteers began searching for Allison. Once information pointed toward San Francisco, attention shifted to the Presidio, the shoreline, and areas near the Golden Gate Bridge.

Contemporary coverage identified the Danville Police Department, Contra Costa County Sheriff’s Office search-and-rescue personnel, National Park Service personnel, and other responding agencies as participants in the search effort. Marin County authorities also provided assistance.

Hundreds of volunteers became involved, reflecting the extraordinary level of concern among Allison’s classmates, neighbors, and the wider community. Online appeals helped spread awareness of her disappearance and encouraged residents to assist with the search.

Evidence Supporting the Investigators’ Conclusion

By May 25, 2011, authorities publicly stated that they believed Allison had jumped from the Golden Gate Bridge on the morning she disappeared.

San Francisco police officials reported that investigators possessed evidence indicating Allison had entered the bridge at approximately 10:00 a.m. on May 23 but had not been observed leaving it. Officials did not publicly disclose every detail of that evidence in the contemporary reporting.

Investigators also considered the directions found on her computer, the location of her bicycle, and the notes she had reportedly left behind. Together, these circumstances supported the official assessment that Allison had apparently died by suicide.

Although the Golden Gate Bridge was equipped with surveillance cameras, the available reporting did not establish precisely what footage, if any, was used to reach the investigative conclusion. It would therefore be inaccurate to describe specific recorded images of the incident as publicly verified evidence.

Search Operations Shift to Recovery

On May 25, authorities announced that the ground search had ended and that operations had shifted toward recovering Allison from the waters near the Golden Gate Bridge.

Danville Police Chief Steve Simpkins publicly expressed sympathy for the Bayliss family following the announcement. The transition from a search for a missing teenager to a recovery effort marked a devastating change for those who had been hoping for Allison’s safe return.

Despite the investigative conclusion, Allison’s remains were not recovered according to the available public case accounts. The absence of recovered remains is an important distinction between the authorities’ assessment of what happened and the physical confirmation that a recovery could have provided.

Community Response and Memorial Services

On May 25, 2011, approximately 2,000 people gathered at a candlelight vigil in Danville to remember Allison and support those affected by her disappearance. Friends, classmates, teammates, and community members shared memories of her kindness, athletic accomplishments, and musical talent.

On May 30, 2011, Allison’s family held a public celebration of her life at Community Presbyterian Church in Danville. The family invited attendees to wear blue and bring photographs or memorabilia to contribute to a scrapbook.

In a public statement, her family expressed gratitude for the extensive assistance and compassion shown by volunteers and community members. Their words reflected both the depth of their loss and the importance of the support they had received.

Theories and Unresolved Questions

The disappearance of Allison Bayliss differs from many long-term missing-person investigations because authorities publicly identified what they believed had happened within days of her disappearance. The central investigative conclusion was that Allison had apparently died by suicide at the Golden Gate Bridge.

This conclusion was supported by multiple reported circumstances, including her travel toward San Francisco, the discovery of her bicycle, information from her computer, and evidence concerning her movements on the bridge.

There is no verified public evidence in the sources reviewed establishing that Allison was abducted, murdered, or the victim of another person’s criminal actions. No officially identified homicide suspect, arrest, or murder prosecution was located in connection with her disappearance.

Why Does Allison Remain Listed as Missing?

Although authorities concluded that Allison apparently died, the California Department of Justice continues to maintain a missing-person record under her name. The Charley Project also lists her case as lost/injured missing.

These listings are consistent with the publicly reported fact that her remains have not been recovered. A missing-person record does not, by itself, contradict an investigative assessment of a probable death.

However, the continued public listing should not be interpreted as proof that investigators are pursuing an unidentified offender or a previously undisclosed criminal theory.

Questions That Remain Unanswered

The most significant publicly unresolved issue is the absence of recovered and identified remains. Without a confirmed recovery, the available public record does not provide the same degree of physical confirmation that would exist following a forensic identification.

Another limitation concerns the precise evidence used to reconstruct Allison’s final movements. Authorities publicly described their conclusions, but contemporary reports did not disclose a complete evidentiary record.

These gaps should not be used to suggest unsupported alternative scenarios. The available evidence supports the historical investigative conclusion, while the lack of a confirmed recovery remains a factual limitation.

Latest Publicly Available Investigative Updates

As of October 31, 2026, the publicly available case information reviewed does not establish a recent investigative breakthrough, recovery of Allison’s remains, new forensic identification, or change to the original investigative conclusion.

Allison remains listed in the California Department of Justice missing-person database. That official listing identifies May 23, 2011, as her last-seen date, Danville as her last-known city, and the Contra Costa County Sheriff’s Office as the reporting agency.

The state’s record also provides the case number SP1109049. The continued availability of this record is an important resource for anyone with credible information, but its presence does not establish that a new investigative development has occurred.

The Family’s Mental Health Awareness Efforts

One of the most significant publicly documented developments after Allison’s disappearance occurred in February 2012, when her father, David Bayliss, discussed plans for a community benefit connected with Alliy’s Hope Foundation.

The proposed event was intended to raise awareness of youth depression and suicide prevention. During public discussions about the event, David explained that Allison had experienced a prolonged struggle with depression and described the family’s desire to help others through education and community support.

The family’s advocacy represented an effort to transform a deeply personal tragedy into greater awareness of mental health challenges affecting young people. The 2012 planning discussions are historically documented; they should not be confused with a newly announced 2026 initiative.

No Publicly Confirmed Recent Breakthrough

No publicly confirmed recent investigative developments were located in the sources reviewed. In particular, no verified announcement was found identifying newly recovered remains, a DNA-based identification, a genetic genealogy breakthrough, an arrest, or a newly established criminal explanation for Allison’s disappearance.

Some historical news articles remain accessible on websites that display more recent page-update dates. Such website maintenance or republication information does not necessarily represent a new development in the underlying investigation.

Anyone seeking the most current official case status should contact the investigating agency or consult the California Department of Justice missing-person record.

Conclusion and Public Appeal for Information

The disappearance of Allison Taylor Bayliss on May 23, 2011, devastated her family, friends, classmates, and the Danville community. What began as an urgent search for a missing 15-year-old became an investigation in which authorities concluded that she had apparently died at the Golden Gate Bridge.

Although investigators established a probable explanation for her disappearance, the absence of recovered remains has left an important part of the case unresolved in the public record. Allison continues to appear in California’s official missing-person database.

Her story is also remembered through the compassion of those who searched for her, the extraordinary community response to her disappearance, and her family’s efforts to increase understanding of youth depression and suicide prevention.

Anyone possessing credible, previously unreported information relevant to Allison’s disappearance or the possible location of her remains is encouraged to contact the Contra Costa County Sheriff’s Office at (925) 335-1581 and reference case number SP1109049.

Allison deserves to be remembered not only for the circumstances of her disappearance, but also for her life: her academic achievements, love of swimming and music, friendships, and the kindness that those closest to her continued to describe after she was gone.