Regular service on the A, B, C and D trains resumed Wednesday morning after an A train derailed in Harlem Tuesday, injuring 39 commuters, the MTA said.
The train derailed at the 125th Street station due to an unsecured replacement rail on the tracks, the MTA said.
The accident damaged track, signal and switch infrastructure, causing service changes to be in effect for nearly 24 hours after the derailment.
Full service began again at about 9 a.m. Wednesday, the MTA said.