St. Louis, MO (KTVI) -- Three people are dead and four were injured after a boiler exploded at a box company in Soulard. It happened shortly before 8 a.m. at the Loy-Lange Box Company located at 222 Russell Boulevard.

Bommarito Automotive SkyFOX Helicopter was over the scene.

According to St. Louis City Fire Chief Dennis Jenkerson, a van-sized piece of the boiler went air born and crashed through the roof of Faultless Healthcare Linen, located at 2030 S. Broadway.

There are three confirmed fatalities.

Two people are in critical condition and two others are seriously injured. Jenkerson says it's unclear if anyone was working on the boiler at the time.

The St. Louis Fire Department says the explosion is affecting three buildings with debris. The Collapse Rescue Task Force along with the St. Louis Metropolitan Police Department are investigating.

Russell, east of Broadway, is blocked at this time. Drivers are encouraged to avoid the area.