Updated

Authorities say four people were hurt when one of San Francisco's historic cable cars jarred to a sudden stop while traveling through downtown.

Municipal Transportation Agency spokesman Judson True says two passengers, the cable car's gripman and conductor were hospitalized on Saturday after the accident. Their injuries are not life-threatening.

The cable car on the Powell Street line came to a quick halt after a problem with an underground cable forced central control to shut the system down automatically.

The Powell line has been shut down and is expected to resume Sunday morning.