Bryan Bonilla, 34, and Alex Wix, 21, dead, two others hospitalized after chemical waste tank explodes on 2nd Street in Guthrie, Kentucky

Near the end of the process around 1 p.m., white smoke or steam was seen coming from the area of the truck, which was parked directly in front of the building, according to Todd County Emergency Management.

Within minutes, the tank exploded and struck two employees, killing one. Also injured was the driver of the truck, a Guthrie city employee, and another Quick Turn employee.

The Kentucky State Fire Marshall and the Kentucky Environmental Cabinet are investigating the explosion and at this time authorities believe that for some reason an organic fat such as cooking oil became mixed with the alkaline wastewater in the tank which resulted in an exothermic saponification reaction.