A long-awaited trial has begun into Greece’s worst train tragedy, which killed 57 people in 2023, leaving the entire country in shock.

Thirty-six people face charges and more than 350 witnesses are due to be heard at the trial that opened in the central city of Larissa, near where a freight train and a passenger train collided on 28 February 2023.

Among those to testify are survivors and family members of the victims, some of whom are believed to have burned to death after surviving the initial collision. Most of the dead were students returning from a carnival weekend.

Before the trial opened, Pavlos Aslanidis, whose 26-year-old son, Dimitris, died in the disaster, and who heads the Association of Victims’ Families, told reporters: “This trial is starting with great delay …what we want is exemplary punishment of those responsible.”

The accused include the station manager on duty on the night of the crash, other railway officials and two Italian former employees of the trains’ parent company, Ferrovie dello Stato.

The two trains had run on the same track for more than 10 minutes without triggering an alarm. The disaster exposed the parlous state of the Greek railway network’s safety systems – despite EU grants for their modernisation, and repeated warnings from unions.

The trial is expected to last several years. Thirty-three of the defendants face criminal charges and risk prison sentences of up to life imprisonment. None of the accused are currently in prison, though some have served time in pre-trial detention.

The head of the European Public Prosecutor’s Office, Laura Kövesi, said the collision could have been avoided if the signalling system had been modernised in time using EU funds.

Train workers are staging a 24-hour strike Monday in what their union has called “an act of collective remembrance, protest, and democratic vigilance”.

Because of the number of participants, the trial was moved to a lecture hall at the University of Thessaly in Larissa.

The disaster sparked widespread anger in the country that has never subsided. Tens of thousands of people joined protests nationwide to mark the accident’s third anniversary last month.

The accused include Vassilios Samaras, the duty station manager who was arrested the day after the collision, and two other station managers who had left their posts before the end of their shift.

They are accused of having committed “acts dangerous to the safety of railway traffic … resulting in the death of a large number of people and serious bodily injuries to a large number of people”, according to the indictment seen by Agence France-Presse.

Managers and employees of the Hellenic Railways Organisation (OSE), the rail network operator, are also on trial, as well as two senior transport ministry officials and two Italian executives from Hellenic Train, a subsidiary of Ferrovie dello Stato.

No political official will be in the dock, fuelling resentment at a time when the conservative government of the Greek prime minister, Kyriakos Mitsotakis, has already been fiercely criticised for what is widely seen as a disastrous handling of the disaster.

There are also claims by the opposition and civil society that officials are shielding those responsible. Two former government members are under investigation, but neither has appeared before a court. Valuable evidence was also lost when, just days after the collision, a bulldozer levelled the site.