JUST A DAY after a devastating safety report that excoriated the culture at the MBTA, passengers documented dramatic sparks and smoke on the Green Line at Park Street.

No one was injured in the incident that occurred just before noon Tuesday, according to MBTA spokesman Joe Pesaturo, but northbound service was shuttered and an acrid smell of smoke lingered throughout the station more than an hour later. It also clearly rattled some MBTA riders, and disrupted others.

“The smoke was so thick that you couldn’t see into the tunnel,” said Ky’Ron Owens, who was in the station when the incident occurred.

Owens is the communications director for Boston’s emergency management department, and he tweeted a video of people crossing the trolley tracks in a haze of smoke, like a thick fog.

At first, people in the station seemed confused by the smoke rolling in, but then as it filled the station, “everyone started looking for the exit,” said Owens. Even while passengers were making their own plans for escape, no one used a loudspeaker to tell everyone in the station whether they needed to leave or not, said Owens, who said the T needs to “work on an alert system” for that type of incident.

As of early afternoon, the MBTA was still investigating the cause of the combustion that caused smoke to emanate from an overhead trough containing electrical wiring, according to Pesaturo. The trolleys are powered by an overhead cable.

Workers ventured down the tracks from the Park Street Green Line platform where service was disrupted by some sort of incident involving overhead wires on December 10, 2019. (Photo by Andy Metzger)

On Tuesday afternoon, many passengers standing on the platform seemed unaware of the service outage even as trolley after trolley pulled up, disgorged passengers, and then went out of service.

Jade Olson, a student at MassArt, was on her way to North Station to catch a train home to Swampscott when she was let off at Park Street, unsure about why service was halted or how exactly to make her connection.

“They didn’t make any announcement at all,” Olson said. “They just said, ‘You gotta get off. Last stop.’”

On Monday, a panel of transit experts reported that safety is not a priority at the MBTA, and in “almost every area we examined, deficiencies in policies, application of safety standards or industry best practices, and accountability were apparent.”

One passenger’s video from a trolley on Monday appeared to show bright sparks shooting out from the ceiling and showering down onto the tracks. On Twitter, the MBTA reported it was experiencing a “power problem” that required repairs to overhead wires, and shutdown of service between Park Street and Haymarket.