Hard questions follow on the heels of Toulouse blast

It was perhaps inevitable that the atrocities of 11th September in New York and Washington would overshadow the explosion at the Grande Paroisse fertiliser plant in Toulouse, which occurred ten days later.

But the sheer scale of the explosion, which killed 29 people, is raising questions for the authorities and the plant's owners, French oil giant TotalFinaElf.

An inquiry into the explosion is underway, but the likeliest cause seems to have been a leak of ammonium nitrate from a 300 tonne silo, which was then ignited by a spark. Whatever the cause, the results were devastating. Twenty-two people on site were killed, as well as seven nearby. Some 650 people were treated in hospital for burns and other injuries, of whom 30 are still in a serious condition.

The number of injured has since risen to 3000. Thierry Desmarest, chief executive of Total-FinaElf, described the explosion as an 'appalling tragedy', and visiting the site the following day, said it was 'a sight of shocking devastation, like a vision of horror.'

The explosion left a huge crater on the site, toppled two chimneys and blew windows out across the city centre. The area surrounding the plant was flattened. Local experts say that the blast was equivalent to an earthquake registering 3.4 on the Richter scale.

And yet it could have been worse. The industrial site on the outskirts of Toulouse is adjacent to other plants manufacturing hazardous materials. One of them makes phosgene gas - fuel for the Ariane rocket. Another makes explosives.

Because of the timing of the attack, police were quick to investigate the possibility of terrorism as the cause of the attack. Suspicion initially fell on a Tunisian-born Frenchman who was killed in the explosion. Apparently he had argued with workers who had displayed American flags in sympathy with the victims of the World Trade Centre and Pentagon attacks.

However, the man's family says that he had no interest in Islam, and investigators are playing down this aspect of the enquiry.

Indeed, accident is still the most likely cause, according to the Environment Ministry. 'In an investigation of this nature, every trail has to be followed, but at the present stage of the enquiry there is nothing to suggest that it was anything other than an accident,' a spokesman said.

According to Le Parisien newspaper, the head of the investigation, magistrate Michel Berard, is leaning towards negligence as the most likely cause. He is quoted in the newspaper as saying that the area of the plant where the explosion occurred was 'certainly a place where materials had been stored without too many precautions.'

Another newspaper report, from the Toulouse daily newspaper La Depeche du Midi, alleges that the explosion was caused by a mixture of sulphuric acid with lime and soda powders. This would indicate negligence at the plant, as this mixture is used to neutralise acid spills; under normal procedures, the neutralisation mixture would be disposed of well away from any potentially explosive materials. Grande Paroisse, however, denies any negligence.

The Grande Paroisse board has promised to participate fully in the debates started by the explosion. Thierry Desmarestt and François Cornélis, chairman of Atofina, have discussed the matter with environment minister Yves Cochet and agreed a course of action. 'This is a complex problem,' Desmarchet concedes.

Cornélis says that addressing the question of site location is a long-term goal, part of a three-level response to the disaster. In the short term, it will reinforce safety levels at sites similar to Toulouse, such as by strengthening monitoring teams and reducing inventories. Medium-term, it will carry out a study of its storage practices and industrial procedures, and look at what investments are necessary to improve safety.The company has already set up a six-person internal enquiry team, whose findings will be make public.

TotalFinaElf has also set up a FFr20million disaster relief fund for those hit hardest by the disaster.