Fourteen of the train’s 175 cars derailed, with one car leaking more than 700 gallons of sodium hydroxide– a hazardous chemical used in cleaning agents.
Trains are now moving, D.C. police said.
Officials say the investigation continues, but offered no information about what caused the 175-car train to derail.
The Maryland department of transportation has agreed with a plan to keep the Laurel train stop and add a new full service stop less than half a mile north, in Howard County. But CSX hasn't agreed to the change.
In a letter to CSX, Howard and Laurel officials plead for two full commuter train stops.