SAN FRANCISCO (CBS SF) — Officials with the California Public Utilities Commission early Friday evening confirmed that the agency is investigating two recently uncovered problems with San Francisco Muni’s new fleet of streetcars.

The issues surround the coupling or “shear” pins that connect the streetcars together when they are in service and malfunctioning doors that reportedly have closed on people hands and arms as well as other objects and locked.

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CPUC Director of News and Outreach Terrie Prosper confirmed the investigation shortly before 6 p.m. to KPIX.

“We are aware and are investigating what occurred and why,” Prosper confirmed in an email. “We are looking at both the door concerns and the coupler pin issue on the new SFMTA cars.”

On Wednesday, the San Francisco Examiner first reported about the problem with the new light rail streetcar doors. In the report, the newspaper cited documents that had been obtained that stated some of the doors on the new streetcars were closing and locking on objects and people.

The initial story centered around a report of a Muni rider — an older woman — who may have been injured after the door of a new car closed on her hand and dragged her behind an N-Judah train last Friday afternoon.

On Thursday, the Examiner posted video the paper had obtained of the incident. The 30-second clip showed the woman getting her hand caught in the door and then running along as the train starts to move through the station.

An SFMTA worker and other people on the platform appear alarmed and seem to attempt to tell the train operator to stop the streetcar, but the woman falls to the ground at the edge of the track and disappears from view.

SFGH spokesman Brent Andrew couldn’t elaborate on the woman’s condition but said she’s already been discharged from the hospital.

Muni is in the process of installing new sensors for their vehicle doors. Muni spokesman Paul Rose said the process was underway before last week’s incident.

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“While we meet all of the technical requirements and regulations, we always want to take advantage of technology developments and continue to make improvements to the design,” he said.

“This is why we are currently exploring additional door enhancements on seven trains that have been outfitted with a second sensitive edge. This provides another layer of protection to offset unsafe behavior, such as trying to grab the doors as the train is leaving the station.”

Early Wednesday evening, SFMTA officials confirmed that a shear pin broke off on a Muni train. The incident also happened last Friday.

A shot of the broken shear pin on the new Muni streetcar.

There were no passengers on the train involved in the incident and the cars did not separate.

But the discovery has prompted Muni to check all of its newer trains. The initial inspection revealed a second shear pin that had broken on another train.

As a result, the newer trains are only being used on the J Church line. That’s because its the one line where the trains are not coupled together.

The SFMTA unveiled its new fleet of Muni trains to much fanfare in the fall of 2017. The trains were billed as needing less maintenance and having a better braking system.

The agency plans to continue replacing its fleet with these updated cars over the next few years.

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