A conductor on the Powell Street cable car line was critically injured Monday when a driver struck him as he unloaded passengers at a Chinatown stop.

The collision happened at around 10:35 Monday morning, when the 53-year-old operator stepped off the cable car on Powell Street between Washington and Jackson Streets, San Francisco Fire Department spokesperson Mindy Talmadge says.

He was walking next to the cable car "to help maneuver it on the tracks between Washington and Jackson streets and to assist passengers who were getting off of the cable car," Muni spokesman Robert Lyles tells Bay City News, when the 42-year-old male driver of a minivan struck the conductor.

The conductor was critically injured in the crash, including suffering a broken leg, broken ribs and bleeding to the liver. He's expected to be hospitalized for a week, maybe longer, Lyles says.

According to San Francisco Police Department spokesperson Officer Albie Esparza, the driver who hit the cable car conductor stopped at the scene. Esparza couldn't say if the driver had been cited as of Tuesday morning.

As of publication time, neither Lyles nor Esparza had any more details about the circumstances of the crash. Both say that the investigation into the collision is ongoing.