Plant explosion kills 18

TOULOUSE, France -- When they heard the huge blast, many people thought it was a terror attack. But the explosion that ripped through a chemical fertilizer plant on Friday, killing 18 people and injuring 200, was most likely an accident, officials said.

The explosion leveled buildings and shattered windows miles away, collapsed dozens of roofs and left a brown haze hanging over this southwestern French city that is home to nearly a million people and the country's aeronautics industry. Much of the plant was in ruins and the blast left behind a 50-yard-wide crater.

"We all thought it was a bomb," said Guy Physsens, a truck driver who was delivering supplies to the factory when the blast went off.

"I dropped flat on my stomach, and when I got up, I saw people who were bleeding all over," said Physsens, who stayed on to help rescuers.

The explosion at the AZF chemical plant in an industrial zone south of the city center was on par with an earthquake of magnitude 3.2, the national earthquake surveillance center said.

Sandra Muller, a mother of three reached by The Associated Press, said she felt the jolt in her neighborhood about 15 miles from the site. She feared a plane had exploded.

"We're next to the airport. With everything that's happened, there's a kind of psychosis," Muller said, referring to the Sept. 11 attacks in New York and Washington.

At least 18 people were killed, regional officials said, and 200 people were injured, 50 of them seriously. Late Friday, rescue workers were still searching through the debris for survivors.

City smelled of ammonia

Earlier in the day, officials blocked off the industrial area, evacuated schools, a hospital and other buildings, closed the airport and subway, rerouted drivers around the city and told people to stay home for much of the day as a precaution.

Streets were virtually deserted and the city smelled of ammonia.

There were early concerns the plumes of smoke could be toxic, though officials said that appeared not to be the case. "At the moment the tests of air at the site show no traces of toxicity," regional prefect Hubert Fournier said.

Still, residents were asked to stay in their homes for about six hours and limit their intake of tap water because the explosion site was near a water plant.

The company called the blast an accident, and French radio reported that workers had made an error in mixing chemicals. French President Jacques Chirac, who visited the site, said it appeared the explosion had been accidental.

"The current information leads us to think that it's an accident, although it's probably too early to say that with certitude," Chirac said. If it was an accident, authorities will have to "learn lessons" from the blast, he added.

The AZF plant, where 460 people work, is among 372 sites in France classified under a European Union directive as high-risk, meaning that extra security precautions must be taken.