An explosion at a local waste disposal plant .. sends two workers to the hospital with serious injuries. The facility is on Adams Acres Road ..east of I-95 .. in Saint Johns county. Channel 4's Marques White spoke to neighbors who say they heard a loud boom. 3 3 00-0611-1617-2141-471:18- 1:241:3671156 MW SU: That explosion happened around 745 this morning at Indianhead Biomass. Some people say they're concerned about another explosion happening so close to where they live. Two workers were flown to UF Health Jacksonville after a large tank explosion. 70555 Mary Varnedoe/St. Johns County: "It was quite loud like almost like a cannon going off." St. Johns Fire and Rescue responded to the scene. 70701 Mary Varnedoe/St. Johns County: "I heard the fire trucks. Actually my dogs heard the sirens not long afterwards. When I let him out he was barking at the sirens." Fire investigators say there was no real danger to people who live in the area. 070304 Lt. Jeremy Robshaw/St. Johns Fire Rescue: "Our initial reports say it was some type of a welding operation going on on a tank. There was some residule combustible gas in the area that ignited and caused the explosion. Again, that's our initial report." 71404 MW BRIDGE: you can see the gate to the company behind me. If you come further down the road, you can see this home nearby.Indianhead Biomass accepts residential waste and converts it to biofuel. Mary Varnedoe says she had no idea the company was so close to her home and that she was somewhat concerned.70728 Mary Varnedoe/St. Johns County: A little bit.I probably should be more concerned. But some people aren't really worried. 71100 Billy Angelus/St.Johns County: "I don't think we're in any jeopardy or anything like that. I think it would have to be a pretty big explosion for you know any type of damage to occur a mile away - at least." The State Fire Marshal's Office, the Bureau of Alcohol, Tobacco, Firearms and Explosives, and the Occupational Safety and Health Administration are all investigating. 71322 MW SU: "The company would not comment. We're told the managers went to the hospital where those two workers were taken in serious condition.In St. Johns County, MW, C4, TLS."