A San Francisco woman was killed Monday after she was dragged by a train when the doors closed between her and her dog.
The woman — who was identified by ABC7 as 41-year-old Amy Adams — was on the platform at the Powell Street Bay Area Rapid Transit (BART) station on Monday afternoon with her dog tethered to her waist, the transit system said in a news release.
She initially boarded a train headed for Dublin/Pleasanton with her dog, but decided to off board at the last second. While she made it off the train, her dog did not, according to BART.
The train departed with the dog inside, and Adams was dragged onto the track. The dog was uninjured.
It's unclear if the dog was a service animal. The incident is currently under investigation, BART authorities said.
"This is a tragic loss of life, and we are following all safety protocols," BART spokesperson Alicia Trost said in a statement.
"It was pretty traumatic," Mike Sim, who witnessed the incident, told ABC7. "Everybody was in shock."
Sim said that once he realized what had happened, he immediately called a BART attendant to assist.
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He said, " 'You need to stop the Dublin train that just left Powell Street cause there's somebody stuck on the door' and then she goes 'OK, OK, we'll contact them.' "
BART, as well as the San Francisco Medical Examiner, did not immediately respond to PEOPLE's request for comment.
The National Transportation Safety Board is currently investigating the incident.