At least 9 are dead following a rear-end crash of two Washington, DC Metro subway trains yesterday. The Metro crash, which occurred during rush hour, also injured more than 70 people, United Press International (UPI) is reporting.

Officials are calling yesterday’s Metro crash the worst in the system’s 33 year history. The collision occurred when one train stopped short of the Fort Totten station - near the Maryland border - and was rammed from behind from the second train, UPI said.

The second train came to rest on top of the first - something that indicates it was traveling at a high rate of speed. The Los Angeles Times reported that the crash occurred around 5:00 p.m. on the Metro’s Red Line, one of its busiest routes.

More than 200 emergency workers responded to the scene, where they had to work to release trapped commuters. Six people - including the operator of the second train - were declared dead shortly after the crash. The additional three bodies were discovered late last night, the Los Angeles Times said. In addition, 76 people were treated at the scene. Some were sent to area hospitals, six with critical injuries.