BART service has been plagued by persistent delays this morning after two medical emergencies, a track problem and a disabled train that stopped transbay service for more than 30 minutes, transit agency officials said.

The first problem began around 6:45 a.m. when a Richmond-bound train broke down just outside of the Transbay Tube near the West Oakland station, blocking trains from going into or out of San Francisco, BART spokesman Jim Allison said.

Crews were able to push the train with another train to the 12th Street Oakland City Center station and service resumed as of 7:19 a.m. with residual delays, Allison said.

About 60 people who were on board the disabled train got off at 12th Street and boarded another train, he said.

Two medical emergencies were also reported on separate trains at the Lake Merritt station.

Another problem occurred at the Lake Merritt station when a malfunctioning track switch had to be cranked into the proper position manually.

“It took us some time to do that,” Allison said.

As of roughly 8:20 a.m., BART passengers were still experiencing 10 to 20 minute delays.