As many as 40 vehicles collided in a fiery chain reaction this morning after a tanker truck overturned on a fog-shrouded downtown bridge. At least three people were killed, authorities said.

Police Lt. Roy Johnson described the situation as "total chaos" after the series of crashes on the Tower Drive Bridge, which carries Interstate 43 over the Fox River."There was a fire, a tanker truck involved, multiple cars - many, many cars - people trapped. Many injuries. The bridge was totally closed off and will be for sometime. The fire is out," Johnson said.

He said visibility was "just about down to zero" when the accident occurred. Police Capt. Larry Gille, who was coordiating rescue efforts at the accident scene, said three people had died.

The number of injured and the extent of their injuries were not known by mid-morning. Gille said some people still were being extricated from vehicles. Johnson said the fire probably was set by a ruptured gas tank on one of the vehicles, and spread to the overturned tanker.