The French and Polish presidents have visited the site of a coach accident in south-east France that killed 26 Polish nationals. Nicolas Sarkozy and Lech Kaczynski also visited the hospital in nearby Grenoble where the 24 injured survivors were taken. Fourteen of them are in a critical condition.
The passengers were on their way back to Poland after a two week pilgrimage to holy sites in Spain and France, when the coach smashed through a safety barrier on a steep and winding mountain road.
It plunged 40 meters down the slope and burst into flames.
Investigators will focus on whether the coach had a reinforced braking system required by law for such a vehicle to use the road at all.
A travel company spokesman said the two drivers were experienced and that the coach passed safety tests three weeks ago.
The road is known locally as an accident blackspot. A similar crash in 1973 killed 43 people.