Authorities confirmed two people died from an explosion at a factory in Louisville on Tuesday.The incident occurred at Givaudan Sense Colour in the Clifton neighborhood. The factory produces food coloring.I don't know if I knew it was an explosion initially, but it was just like the whole house shook and stuff was falling off the walls, said Kim Prather.From her home, located just 100 yards from the factory, Prather said she watched as employees evacuated the crumbling structure.All the sudden, when I saw people coming from between the houses, it was like they kept filing out, they were holding their heads and faces, there was blood running down, said Prather.As first responders raced down the narrow street, the University of Louisville Hospital admitted 11 of the factory employees.Dr. Jason Smith with the hospitals trauma center said, As far as the condition of injuries, overall we saw a spectrum of injuries including blast injuries, thermal injuries, and injuries from falling debris.One of those victims died, and hours later, crews learned that another employee died at the scene.Initially, we had been told at the scene, by the business, that all of the employees were accounted for, tragically, that was not the case, explained Mayor Craig Greenberg during a press conference on Wednesday.It took several hours to get to the victim and dig them out, but we wanted to make sure that family has closure and we have respect for those that we lost, added Louisville Fire Chief Brian ONeill.According to authorities, air monitoring indicates that there is nothing hazardous in the sky, and residents who had to be evacuated have since returned home.I know many of you are probably concerned, What happened, why did it happen? And I'm going to apologize in advance, we don't have those answers immediately, that is going to be part of the investigation, said ONeill.The National Response Team from the ATF is assisting with the investigation.