A woman was gravely injured this week after a group of teenagers burst onto a public bus in Marseille, splashed the interior with gas, and set it on fire. All of the passengers got out except Mama Galledou, 26, who suffered burns over 70 percent of her body and went into a coma. Several similar bus attacks have occurred across France in the past few weeks, as immigrant youths mark the anniversary of last years riots. But in the other bus burnings, the attackers let all the passengers off before setting the flames. The riots last year, sparked by the accidental death of two Muslim teens who were fleeing police, lasted three weeks. Rioters burned more than 10,000 cars and firebombed around 300 buildings, mostly in the suburbs of Paris.