An unattached rail joint may have caused a train derailment in France during a busy holiday weekend that left six dead, rail officials said.
Nearly 200 people were injured, including nine in critical condition.
The packed train, which left Paris on Friday evening with 385 passengers, jumped the track about 20 minutes into a scheduled three-hour journey as it travelled through Bretigny-sur-Orge station. It crashed into the platform and some cars tipped over.
Human error has already been ruled out, according to Transport Minister Frederic Cuvillier, and attention has focused instead on the switching system, which guides trains from one track to another. Investigators found that one joint in the switch had disconnected from its normal position, Pierre Izard, an official with the national rail company, SNCF, told reporters.
"It moved into the centre of the switch and in this position it prevented the normal passage of the train's wheels and it may have caused the derailment," he said at a news conference.
Investigators were looking into how this happened since another train had travelled safely through the station about 30 minutes before. In addition, they were trying to figure out why the train's third car was the first to derail. The train was travelling at 85 mph, below the limit of 93 mph.
"The SNCF considers itself responsible," the rail company's president, Guilaume Pepy, said. "It is responsible for the lives of its clients."
The train was about 12 miles into its 250-mile journey to Limoges.
Passengers and officials in train stations throughout France held a minute of silence at noon to commemorate the accident. Hundreds of thousands of people were expected to take trains this weekend for the coast, mountains and to see family.
Summer weekends are always busy on France's extensive rail network, but this weekend is typically one of the busiest since the country celebrates Bastille Day on Sunday.