At least 46 people were killed when a passenger train collided head-on with a cargo train outside the city of Larissa.

Here is what we know so far.

What happened and when?

• A passenger train travelling from the capital, Athens, to the northern city of Thessaloniki collided with a cargo train carrying shipping containers coming from the opposite direction on the same track.
• The passenger train was carrying 342 travellers and 10 crew, while there were two crew members on the cargo train.
• The train left Athens with passengers at 7:22pm (19:22 GMT). Authorities were informed about the accident just before midnight.
• The derailing carriages burst into flames after the collision. Temperatures in one carriage rose to 1,300 degrees Celsius (2,370 degrees Fahrenheit) after it caught fire.
• As of Thursday morning, the death toll was 46.

Where did it happen?

• The crash occurred outside the central town of Larissa, some 376km (235 miles) north of Athens, in the municipality of Tempi.
  

  

What do we know about the casualties?

• Many of the victims were thought to be university students returning to their homes after a long holiday weekend.
• A number of bodies were charred beyond recognition and some passengers were being identified from body parts.
• Relatives of the victims went to a hospital in Larissa where they were asked to give DNA samples to be checked against those retrieved from the crash site.
• Greece’s firefighting service said 57 people remained hospitalised late on Wednesday, including six in intensive care.
• More than 15 others were discharged after receiving treatment.
• More than 200 people who were unharmed or suffered minor injuries were taken by bus to Thessaloniki, 130km (80 miles) to the north.

What went wrong?

• Authorities are still investigating the circumstances that led to the crash.
• Greek Prime Minister Kyriakos Mitsotakis said it happened “mainly due to a tragic human error” but did not elaborate.
• Police have arrested the Larissa station master, who is responsible for rail traffic on that stretch of the tracks. He was due to appear before a prosecutor on Thursday to be formally charged.
• Investigators were trying to determine why both trains were on the same track “for many kilometres”.
• Yiannis Ditsas, head of the railway workers union, told Skai TV that automatic signalling at the crash site had not been working.
• Industry experts say systems that signal whether a track is already occupied by setting off a red light or that automatically operate a switch to divert a train onto another track are not properly maintained.
• “Red lights malfunction very often or they turn on for no reason, and the culture in the Greek rail system is that drivers and station masters have learned to ignore them,” said Al Jazeera’s John Psaropoulos, reporting from Larissa.
• “The last conversation recorded between the station master and the passenger train driver suggests exactly such an incident of simply ignoring the signalling. The station master says, ‘you are good to go, you are good to go,’; the train driver wasn’t sure if the signalling was correct for him to leave,” he added.
• Transport Minister Kostas Karamanlis resigned, saying he was taking responsibility for the state’s longstanding failures to fix a railway system that, he said, “was not fit for the 21st century”.
• Nikos Tsouridis, a retired train driver trainer, said drivers involved in the crash had died “because there were no safety measures”. “And why were there no safety measures? The station master made a mistake, he acknowledged it. But surely there should be a safety mechanism to fall back on,” he said.
• Train unionists say the safety shortcomings of the Athens-Thessaloniki railway line, the main one in the country, had been known for years.
• Greece sold railway operator TRAINOSE under its international bailout programme in 2017 to Italy’s Ferrovie dello Stato Italiane, expecting hundreds of millions of euros to be invested in rail infrastructure in the coming years.

What is the latest on the ground?

• Rescuers resumed a search on Thursday for survivors.
• A total of seven charred bodies were recovered from the passenger train’s third wagon, which served as a restaurant.
• Government spokesman Giannis Oikonomou was expected to update the media around midday on Thursday.
• Authorities have declared three days of national mourning.

How have people reacted?

• Railway workers nationwide walked off the job on Thursday, saying successive governments had ignored repeated demands to improve safety standards.
• In Athens, people in hundreds marched late on Wednesday to protest against the train deaths.
• Minor clashes broke out as some protesters threw stones at the offices of Greece’s rail operator and riot police and set dumpsters on fire. No arrests or injuries were reported.
• Internationally, flags flew at half-staff outside all European Commission buildings in Brussels while world leaders expressed their condolences. Turkish President Recep Tayyip Erdogan and Pope Francis were among those to condole.

What do survivors say?

• Some survivors described the moment when the crash took place.
• “There was panic … The fire was immediate. As we were turning over, we were being burned; the fire was right and left,” Stergios Minenis, a 28-year-old who jumped to safety, told Reuters.
• “Windows were being smashed, and people were screaming … One of the windows caved in from the impact of iron from the other train,” another passenger, who escaped from the fifth carriage, told Skai TV.