SAN FRANCISCO (CBS SF) — A problem with the propulsion system halted a BART train filled with morning commuters inside the TransBay Tube Tuesday, triggering major system-wide delays, officials said.

BART officials announced the delay at about 9 a.m., citing a San Francisco-bound train that was experiencing a propulsion problem, causing it to come to a stop inside the tube.

The train’s operator has put the train under automatic control, allowing it to slowly move toward the Embarcadero station, where technicians stood by, BART spokeswoman Alicia Trost said.

The problem was cleared in less than an hour, but 20 minute delays lingered well into the morning commute.