Officials: At least 2 critical after plant blast

Officials: 10 hurt, at least 2 critically, in explosion at Illinois steel foundry

This image from video provided by KMOV-TV in St. Louis shows an injured worker is helped into a helicopter outside the American Steel plant in Granite City, Ill., Thursday, March 7, 2013, where an explosion injured at least 10 people, three critically. (AP Photo/Courtesy KMOV-TV in St. Louis) TELEVISION OUT

ST. LOUIS (AP) -- Officials say at least two people are in critical condition after an explosion at a manufacturing plant in southwestern Illinois.

Authorities say 10 people were taken to hospitals after the explosion Thursday at the American Steel Foundries plant in Granite City, northeast of St. Louis.

Granite City Fire Capt. Bert Houston says the explosion occurred after gas caught fire in the finishing area of the plant, which makes railcar components. What ignited the gas wasn't known.

Gateway Regional Medical Center spokeswoman Kate Allaria says seven workers treated for smoke inhalation have been released. She says three other injured workers were flown to other hospitals.

A spokeswoman at Mercy Hospital in Creve Coeur says the two victims it received are in critical condition. The whereabouts of the other worker was unclear.