Investigators with the San Mateo County Sheriff's Office as well as the Coroner's Office were looking into what may have contributed to the death.
Officials say the incident happened shortly before 9 a.m. Monday morning in front of hundreds of passengers who had just arrived at the airport and were collecting their bags.
Witnesses tell ABC7 airport paramedics were on scene within minutes but were unsuccessful in reviving the man. An airport spokesperson said the victim appeared to be in his late 50's or early 60's but declined to provide additional information.
Vehicular traffic going in and out of the airport was impacted for nearly two hours following the incident, as both the Sheriff's Office and Coroner's Office sent representatives to conduct a thorough investigation. Arriving passengers were re-routed to other escalators in the terminal as crews cordoned off the impacted area. The scene was cleared by noon and operations were back to normal.
As of Monday afternoon, it's unclear if the now deceased individual suffered a medical emergency before going over the railing, or if the fall was intentional. Witnesses reported hearing a loud commotion before seeing the man fall to the ground.
Airport officials would not confirm if the man was a ticketed passenger, and/or if he was picking someone up at the airport.
The Coroner's Office says it will release the victim's identity once next of kin has been notified.
#BREAKING: Man falls from mezzanine level to ground floor (baggage claim) at #SFO Terminal 3, according to witness at the scene. Happened shortly before 9am. @abc7newsbayarea has confirmed the man did not survive his injuries. Incident is currently under investigation. #ABC7Now— Chris Nguyen ABC7 (@ChrisNguyenTV) May 21, 2018