SAN FRANCISCO—State regulators are investigating an incident involving a Muni train door closing on a woman’s hand, causing her to tumble on to the tracks. They are looking specifically into Muni’s allegedly malfunctioning doors and broken couplers. The California Public Utilities Commission is reviewing the mishap, and putting pressure on Muni to fix two recent safety issues with its new Siemens railcars.

The incident occurred on April 12, while the victim, an elderly woman got her hand caught in the door of the Muni train as she tried to board. She was dragged for several feet before freeing her hand. She fell and sustained a serious injury and was taken to a local hospital for treatment. The name of the victim has not been disclosed to the public.

The accident was captured on Muni’s video sruveillance, first obtained by the SF Examiner. It shows an elderly Asian woman approach the train and try to open the door. Moments after, the woman’s hand gets caught, the video shows a station master waving for her to get away from the train. The station master then begins warning others to stay away from the train.

The California Public Utilities Commission reviewed video of the accident at the Embarcadero Station on Friday, April 19 and is expected to inspect the coupler system next week. Last week, Muni discovered two failures of shear pins, the steel rods that couple the trains together and designed to break to offset the collision of linked cars.