The lack of an automated braking system may have contributed to this week's deadly double train collision in southern Italy, an investigator said Wednesday, as teams tried to sort out the reasons for an accident that left 27 dead.
"There are no automatic systems in use on this stretch," railway police chief investigator Giovanni Meoli told the newspaper Corriere della Sera. "It still uses the old telephone relay system."
Recovery teams have already found the data recorder of one of the trains as they try to determine whether human error or technical failure was responsible for the accident. Prosecutors in the nearby city of Trani are investigating charges of negligent homicide, though the charges are not targeted against any particular person.
The two-train collision happened on a single-track line between Corato and Andria, north of the port city of Bari on Tuesday morning. About 50 people have also been reported injured.
The stretch where the accident occurred had long been earmarked for renovation to turn it from a single-track stretch to a two-track one, but that work was routinely delayed. Because there was no automated system, station chiefs would talk by telephone to inform one another when the stretch was open for traffic.
"This stretch is already half outfitted with an automated control system," said Massimo Nitti, head of the Ferrotramviaria railway company. "Unfortunately, not in the part where the accident happened.
"We have to understand where the chain of control broke down," he said.
Citing investigators, Italian news agency ANSA reported that the problem might have been caused when a delayed train slipped past unnoticed, leading station chiefs to think the tracks were free when they were not.
"The problem is not the single track - which is a situation that exists in about half of Italy - but the technology that should have prevented this accident," said rail expert Giuseppe Sciutto of the University of Genoa, speaking to the Adnkronos news agency.
Aid workers spent the night looking for victims and survivors beyond those already tallied. Much of the attention focused on the two front cars, both destroyed by the impact.
"We don't know the overall number of passengers because this isn't an aeroplane and we don't have any lists," said prosecutor Francesco Giannella. Investigators have not ruled out that some of the dead may be foreigners.
The trains, one built in 2005, the other in 2009, were travelling at about 100 kilometres per hour when they collided on a curve in the track.