GRANITE CITY — Two men remain in critical condition and eight others were injured after an explosion Thursday morning at Amsted Rail.

The two men critically injured were airlifted to Mercy Hospital St. Louis in Creve Coeur, Mo.

A third person was airlifted from Granite City to Missouri, according to Erin Echelmeyer, spokeswoman for Gateway Regional Medical Center in Granite City. However, Echelmeyer did not know further details about the third airlifted worker's whereabouts.

A total of 10 injured workers were transported to Gateway on Thursday morning, Echelmeyer said. Of these 10, three were airlifted and seven were treated and released from Gateway.

United Steelworkers of America Local 1063 President Robert Lott, who represents workers at the plant, said he was in the building and standing about 100 yards from the scene of the explosion when it happened. Lott said Reginald Golliday, who has worked at the railroad carriage manufacturing plant for the past 17 years, may have suffered two broken legs, a large gash on his forehead and internal injuries. He also said that Danny Wilson, a 10-year veteran at the plant, suffered a broken leg and internal injuries.

Granite City Fire Department Assistant Chief Jim Snelson said the fire department was called at 8:10 a.m. to the plant at 1700 Walnut St.

Lott said the explosion caused a blackout at the plant. He said he believed the blast was caused by a gas leak under a wooden platform where workers were standing.

"I could see flames, initially, and then the visibility went down to zero from the dust that fell from the rafters," Lott said.

Lott said a similar explosion happened at the factory about 20 years ago.

In Collinsville, International Brotherhood of Electricians Local 309 Business Manager Scott Hassall said one electrical maintenance worker who was on site at the time of the blast was not injured.

Hassall also said the Occupational Safety and Health Administration reported to the scene Thursday morning to investigate. Karl Armstrong, OSHA assistant area director in Fairview Heights, confirmed that an investigation was under way but did not provide any further information.

Lott said that after the blast, workers were directed to the cafeteria at the back of the plant. Workers leaving the plant about noon told reporters that they were told not to speak to the media.

Representatives from Amsted Rail could not be reached for comment.

Federal officers partially inspected the site in 2011 and 2012, but did not cite Amsted for any violations, according to the records of the OSHA within the U.S. Department of Labor.

Both inspections were for health-related complaints -- not safety violations. The latest inspection of the site was on July 31 in response to a complaint about workers exposed to high heat.

Contact reporter Will Buss at wbuss@bnd.com or 618-239-2526. Contact reporter Scott Wuerz at swuerz@bnd.com or call 618-239-2626.