Four people were dead and 10 critically injured after a local train derailed between Segrate and Pioltello stations near the northern Italian city of Milan on Thursday, emergency services told AFP. The accident took place around 7 am (local time) when the train was heading to Milan’s Porta Garibaldi station from Cremona.

The train was not speeding when the accident took place, a spokesperson for Trenord, which operates the train services, told Reuters. The police said a glitch in the track switch may have caused the accident, according to BBC. Milan’s public prosecutor’s office said an investigation was on.

Eyewitnesses said the train was shaking for a few minutes before it went off the tracks. Several people were rescued from the wreckage of the carriages. A team of 90 firefighters were at the spot to carry out rescue operations. The accident triggered traffic snarls and disrupted rail services briefly.

In July 2016, 23 people had died after two trains collided in the southern Puglia region. Several rail executives, including the former head of Italian railways, were held responsible for poor infrastructure that led to the accident.