Transit A, B, C and D train service resumes after derailment in Harlem, MTA says Workers at the 125th Street station in Harlem survey damage after a train derailed on Tuesday, June 27, 2017. Photo Credit: Transport Workers Union, Local 100 By amNY.com staff Updated June 28, 2017 9:29 AM Print Share fbShare Tweet Email 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. By amNY.com staff Share on Facebook Share on Twitter Comments We're revamping our Comments section. Learn more and share your input.