The union representing SEPTA operators and maintenance workers released a video Thursday of teenagers beating a 55-year-old track worker earlier in the week and said the transit agency can no longer protect its employees from frequent assaults.

Leaders of Transit Workers Local 234, which represents about 5,000 SEPTA employees, called on Transit Police Chief Thomas Nestel to resign.

“It’s not personal, but it’s a war out there, and if your wartime general isn’t winning, you need a new general,” said Willie Brown, president of the union.

Nestel, in an interview, said he respects Brown standing up for his members but does not intend to quit. He said SEPTA is taking steps to improve safety on transit for workers and riders.

“We share the same frustration,” Nestel said. “We’re in a city that is struggling with violent crime, and we are working to fight it” on the SEPTA system.

On Monday at 11:30 p.m., about a dozen young people jumped and attacked the worker in a corridor in the 15th Street/City Hall subway station, according to transit police. He suffered a concussion and is recovering, Nestel said. No arrests have been made, and an investigation is continuing.

SEPTA video, obtained by the union, captured the unprovoked assault. Brown said he was concerned what might happen as Philadelphia public schools reopen.

“Many students ride the system to school,” Brown said. “How can parents put their kids on public transportation if we can’t even give half an assurance they will be safe?”

» READ MORE: SEPTA is closing El station in Kensington to fix elevators damaged by urine, trash

Kensington’s Somerset Station on the Market-Frankford Line is scheduled to close Sunday, in part because of an influx of homeless people and drug users seeking shelter inside. Riders and workers have complained of harassment. SEPTA also wants to repair the station’s two elevators, inoperable because of damage from urine and trash.

SEPTA ridership is down about 65% on transit — subways and buses — and 85% on Regional Rail from pre-pandemic levels, meaning many fewer members of the public to watch over the system and report problems. Nestel said crime on SEPTA stayed level between 2019 and 2020 but has spiked a bit early this year.

Reports of assault, harassment, and threats against SEPTA employees did fall between 2019 and 2020 but not as steeply as ridership. Workers reported 260 such incidents in 2019 and 174 last year, a reduction of about 33%. The most common 2020 incidents: harassment and being spit upon.

Within the next few weeks, SEPTA plans to hire a contractor to deploy 60 temporary security guards who will be posted at the entrances to stations along the Market-Frankford Line between 15th Street and the Frankford Transportation Center, Nestel said. They will not be employees of the transit agency, and officials said no cost estimate was yet available.

SEPTA also wants to assign people to monitor video feeds live “as additional eyes on the system” who can catch problems and raise a quick police response, Nestel said.

The Transit Workers local has been recommending that security cameras be monitored live in talks about employee safety with management, Brown said. He also believes SEPTA should distribute footage of suspects to the public and offer rewards.

“We’re going to start offering rewards if they don’t,” Brown said. “We can’t sit back and let that [violence] happen.”