Reports of potential “human error” have emerged after Tuesday’s deadly train crash in Greece.

As the search for missing passengers continues, an investigation launched by the European Public Prosecutor’s Office (EPPO) has pointed to failings in the train’s signaling system and a lack of investment in the rail service over the past decades.

According to researchers, if this equipment was functional, it could have prevented the train accident that killed more than 50 people.

But anger is growing as thousands of people, including rail workers, took to the streets on Thursday to confront the government over a degrading rail system.

“We are angry at the company, at the government and previous governments that did nothing to improve conditions on the Greek railway,” said pensioner Stavros Nantis in Athens.

One minister said austerity during Greece’s economic crisis in the 2000s had contributed to a lack of investment in the railways.

So far, the investigation has concentrated on the cause of the explosion that occurred after the collision.

The former station master in Larissa is facing very serious charges, after being charged on Thursday with disrupting transport security, which carries penalties ranging from ten years to life in prison. “He took responsibility for his part, what counts is not looking for the tree but for the forest,” his lawyer said.

According to the station master’s colleagues, he was inexperienced for the job and had only been on duty since January and should not have been alone on such a difficult shift. “The regulation does not say anywhere about the experience of station masters. After the training, he takes on assignments,” replied the general secretary of The Hellenic Railways Organisation.

On Wednesday, authorities released an audio document in which the station manager was heard telling one of the drivers involved in the crash to ignore a red light.

So far, the death toll has reached 57 and about the same number are still missing. 48 people are still in hospital, of which six are in intensive care units.

The fire service said the temperature inside the first carriage – which burst into flames – had reached 1,300C, making it “difficult to identify the people inside”. As a result, the victims’ families are still awaiting DNA test results to help identify the victims.