A fire and small explosion took place at the St. Paul waste water treatment plant at 2400 Childs on Tuesday morning, one employee was hospitalized with minor injuries.
Dispatch confirmed around 10:15 a.m. that the fire station was empty while black billowing smoke was seen from a distance.
Officials confirmed that the fire was caused by use of a saw during demolition.
At one point, an employee was unaccounted for and missing, then later found in a safe place.
St. Paul fire department said a small explosion occurred about an hour later inside the facility, while flames were going through the roof.
Reports are that firefighters may have to undergo contamination after being exposed to the chemicals.