A Muni Metro light-rail vehicle left the station without its operator Wednesday morning, said John Haley, transit director of the San Francisco Municipal Transportation Agency.
The incident occurred on an outbound KT-Ingleside/Third Street line as the vehicle was leaving the Castro station about 10:15 a.m. The operator reportedly got out of the vehicle to check on a problem with a door and may not have activated the train's emergency brake, a red button known as the mushroom, Haley said.
After the operator shut the door, the system believed the train was ready and proceeded under automatic control to roll away without the operator.
There were about 30 passengers on the train, one of whom stopped the train with the red-lever emergency brake accessible to passengers between the Castro and Forest Hill stations. A contractor who maintains Muni's fare gates was on the train and encouraged the stranded passengers to stay in the train and wait for help, Haley said.
A mechanic was dispatched to the scene and the train was brought into Forest Hill Station at 10:35 a.m.
"It took about 14 minutes to deal with the situation," Haley said.
Agency officials will be investigating whether the operator forgot to apply the emergency brake or whether there was a problem with the train.
No passenger was injured during the incident, Haley said.