MTA workers putting the finishing (almost) touches on the newly rebuilt Myrtle Viaduct on Thursday, April 26. Marc A. Hermann / MTA New York City Transit

On Friday, the MTA sent out a press release proclaiming full M service would resume today, April 30, as planned after eight months of construction, “on time and on budget, and made resilient for decades to come.”

“Decades,” it turns out, really meant “a few hours,” after which J and M service in Brooklyn was suspended and trains were stranded on the Williamsburg Bridge for more than half an hour, because of switch problems at Myrtle Avenue, the exact junction where service had been restored this morning.

According to internal MTA work orders, two newly installed switches near the Myrtle Avenue station were not working as of 11:30 p.m. last night, mere hours before service was supposed to resume. Crews worked throughout the night to get them into working order and stationed workers nearby in case something went wrong during the morning rush hour. By 4:30 a.m., half an hour before the eight-month construction project was set to officially end, the switches were back in working order.

But at 11:49 a.m., one of the switches broke again, and service was suspended on the J and M in Brooklyn.

J and M train service changes are because of switch problems at Myrtle Av. Visit https://t.co/vhZQ2kZ2vb — NYCT Subway (@NYCTSubway) April 30, 2018

Update: There is no J train service between Essex St and Broadway Junction in both directions.

There is no M train service between Essex and Middle Village-Metropolitan Av in both directions.

These service changes are because of switch problems at Myrtle Av. — NYCT Subway (@NYCTSubway) April 30, 2018

Update: There is no M train service between W 4 St-Washington Sq and Middle Village-Metropolitan Av in both directions.

As an alternate customers are advised to use the or train or B24, B38, B46, B54, Q54 bus service. — NYCT Subway (@NYCTSubway) April 30, 2018

Update: I've been stuck on a J train on the Williamsburg Bridge for 35 minutes cuz the @MTA sucks https://t.co/AbvuwweIQY — Shwax (@Shwax) April 30, 2018

Because workers were still on site as a precaution, they were able to fix the switch fairly quickly. By 12:25 p.m., service on the J and M had resumed.

The switch issues highlight the rush the MTA was in to resume M service. The project was scheduled to be finished by “April 2018.” So in order to proclaim the project “on time and on budget,” service had to resume no later than today. As the M train project was the last major infrastructure initiative that could possibly have gotten finished on time and on budget before the L train shutdown begins next year, the transit authority was under pressure to prove it could accomplish such a feat. And while it can still claim to have done so, we now know how close the authority really cut it.