A party of 23 staff and pupils from St James's CE grant-maintained school, Bolton, plunged 70 feet down a ravine off the mountainous road between the villages of Longfoy and Notre Dame du Pre. Nicola Moore, 16, was killed instantly and two 14-year-olds, Robert Boardman and his best friend Keith Ridding, died later in hospital.
The French coach, driven by a British driver, was rented from a local company when the one hired from a Manchester firm broke down last weekend. The Manchester coach had seatbelts but its replacement did not and, when the coach rolled over the pupils were thrown around the interior.
Since February, British law has required coach operators to fit seatbelts to minibuses carrying more than three children and to coaches manufactured since 1988. Vehicles made before that date must be fitted with belts by February 10, 1998. But in the rest of the EU, coach operators will not be obliged to fit seatbelts on new coaches until October 1, 1999.
The Royal Society for the Prevention of Accidents recommends that schools and voluntary organisations only hire coaches with seatbelts from companies with drivers and escorts trained to deal with children.
"This tragic accident strengthens our case that all vehicles should have belts on every seat," said a spokesman.
Pat Harris, founder of Belt Up School Kids, the school transport safety organisation, is pressing for an EU-wide school transport Act.
The children and teachers involved in the accident were on a water-sport adventure trip as part of the 900-pupil comprehensive school's "curriculum enhancement" week.
St James's closed for lessons for the week, but kept its doors open so that parents and children could meet counsellors and clergy.