Over 20 are killed and 160 injured from a train that derailed in Moscow on Tuesday.

The train derailment has caused a great stir during the morning commute. The derailment happened on the metro’s Dark Blue Line. The train came to a stop and then derailed between Slaviansky Boulevard and Park Pobedy stations.

Twelve bodies were found in the wreckage of the metro. Seriously injured passengers were carried away on stretchers. They were immediately brought to hospitals. All of the remaining passengers were finally able to be evacuated by the middle of the day. An investigative committee is looking into the incident that took place at approximately 8:35 a.m..

Moscow’s deputy mayor, Peter Biryukov, said “The cause is not known, the work continues,” according to Reuters.

The Slavyansky Bulvar metro station has been temporarily closed, according to The Moscow Times.

The metro serves as many as 9 million people. Attacks from militant forces have been the cause of subway incidents in the past. Islamist terrorists carried out metro bombings in Moscow in 2010.