(Bloomberg) — Two Moscow subway workers were detained in the investigation into yesterday's train crash, which killed 22 people and injured 162, the deadliest incident in the city's underground system since 2010 suicide bombings.

The workers are suspected of violating safety regulations by improperly installing the switch that failed when the train was changing tracks, causing the three lead wagons to derail and trailing cars to jack-knife, the Investigative Committee said in a statement on its website.

Nineteen people died on the scene and three more succumbed to their injuries in the hospital, according to Emergencies Ministry. More than 100 people were still being treated by midday. Rescue workers evacuated more than 1,200 people from the tunnel where the crash occurred during morning rush hour, between the Slavyansky Bulvar and Park Pobedy stations in western Moscow. The train, on the dark blue line that bisects the city, was heading away from downtown when it crashed.