French investigators had previously concluded that the explosion of 250 tons of ammonium nitrate was an accident. After several very curious discoveries however, they are rethinking the cause and have raised the possibility that it may have been a deliberate act of sabotage by a known sympathizer of Islamic fundamentalism, who was also killed in the blast.

http://www.usatoday.com/news/attack/2001/10/04/toulouse.htm

Personally, I'm very, very saddened at the possibility, however remote, that French citizens may have been killed because they displayed an American flag in solidarity with the victims of the Sep. 11 terrorist attack, and thus triggered the rage of the suspect at the work site.