As Metro riders crowded platforms and endured delays early Thursday, they had plenty of time to let the latest bad news sink in about the agency’s safety lapses.

Metro’s new 7000-series train cars are apparently prone to delivering electrical shocks to the employees who work on them. This news led to a safety stand-down by Metro, a protest by Metro’s largest union, an unhappy Thursday morning commute, and some of the usual Metro-said, union-said back-and-forth, as seen earlier this week when both sides bickered about a broken cement mixer. Riders had the usual questions, like so:

Metro’s latest unsettling safety incident occurred Saturday evening, when a rail-car mechanic received a jolt of electricity while inspecting the train, according to Amalgamated Transit Union Local 689. The union, saying the incident could have killed or seriously injured the mechanic, demanded a halt to the inspections and accused Metro of covering up previous incidents with the cars. The union also said this was the fourth such incident this year.

Metro, in an anodyne statement posted just about the time Thursday’s rush hour was underway, explained that the electrical short has something to do with the mechanisms that return electrical current from the cars to the rails and that inspections of the rail cars had been temporarily suspended, pending review. Oh, and expect delays this morning, etc.

My colleague Martine Powers reports that the Federal Transit Administration (FTA), which has safety oversight over Metro, has been alerted to this “hazardous condition.” An incident report obtained by The Washington Post says the mechanic suffered a “light” shock that left no visual burns. He was taken to Inova Fairfax Hospital for evaluation.

People in the Twitterverse were ticked off — and rightly so — about the delays, about the latest evidence that Metro can’t fly straight and about the lack of transparency.

Metro took most of the heat for another rough ride, as it should — but where was the union? If this was potentially deadly, and Metro wasn’t doing anything about it, then why didn’t the union speak up after the first incident?

David Stephen, a union spokesman, said Wednesday was the first the local had heard about the incident with one of its mechanics. “Once we learned of it we began to research and found out about the previous [three] incidents,” Stephen said in an email.

Meanwhile, Metro issued a statement at midday saying that engineers from the agency and the train car’s manufacturer had completed a review of inspection procedures for the grounding mechanism and found them to be appropriate and consistent with the manufacturer’s guidelines.

“As such, mechanical inspections of 7000-series railcars will resume this afternoon following additional safety briefings with employees to reinforce these procedures,” the statement says.

In addition, spokesman Dan Stessel said in an email that the situation never posed a threat to riders, as there are “secondary grounding systems” that protect against electrical current passing through areas that could come in contact with them. He also said no public advisory had been put out because there was no threat to the public. He further characterized the nature of the hazard to Metro workers inspecting the trains:

“To be clear, electrical energy is always hazardous if not dealt with properly. The specific concern that was identified recently involved maintenance employees conducting inspections on an electrical component under the car. Metro took steps to mitigate the hazard, including requiring that 7000-series railcars be powered down while undergoing maintenance in the shop.”

Back to good, or at least normal, perhaps. But yet again, Washington was left standing on the platform in need of a ride, while Metro and its union bickered — and this time about something more critical than a broken-down cement mixer.

–This post has been updated.

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