On the afternoon of Jan. 4, 1987, the crew of a Conrail locomotive traveling near Baltimore failed to respond to stop signals and hit an Amtrak train traveling from Washington, D.C., to Boston. Fourteen passengers on the Amtrak train were killed. Post-accident testing revealed that both the Conrail locomotive engineer and brakeman had been using marijuana.

This tragedy was part of the impetus for U.S. Department of Transportation (DOT) regulations mandating drug and alcohol testing for various categories of transportation employees.