A Metropolitan Transportation Authority spokesman said that the derailment happened shortly after 4 a.m. Thursday at the Stamford train yard. Spokesman Dan Brucker says it was a "slow-speed event" with no passengers aboard and no one was injured.
Brucker says the mishap limited the number of trains that could leave the station, and there were fewer cars per train. He says some express trains would be making extra stops.
Metro-North also suspended service on the New Canaan branch because of the derailment and ran buses instead.
Brucker says it's not clear why the train in Stamford rode up over the tracks.