An explosion and fire Wednesday afternoon at a metal fabrication plant in Minneapolis badly injured two workers, authorities said.

The blaze occurred at Metal-Matic, 629 SE. 2nd St. SE., across the Mississippi River from downtown.

The two employees were taken to a hospital with serious burns and other injuries, said Assistant Fire Chief Bryan Tyner.

Tyner said the blast and fire are believed to have occurred in one of two dust collectors.

Robert Vignalo, a worker who was waiting for his shift to start, said the explosion occurred in a shed and happened near the end of the plant's first shift and while other employees waited in their vehicles for the next shift to start.

"Things were raining down on our cars," he said. "I ran inside because I have friends inside."

He said the area was immediately smoky, and a supervisor asked if anyone wanted to go home, but Vignalo waited to see if he could go back inside and help clean up the mess.

A photo from Minneapolis Scanner, a Facebook page that tracks police and fire transmissions, showed a substantial amount of smoke coming from the building. By about 3:45 p.m., the blaze was under control.

"I heard a loud banging noise that shook my entire apartment building," said Drue McLean, who lives directly behind the building. "Shortly after, I saw clouds of smoke through my window. When I went outside, black smoke was coming out of the Metal-Matic building."

CenterPoint Energy shut off the natural gas flow to the building, said utility spokeswoman Becca Virden, who added that the incident "is not natural-gas-related."

Founded in 1951, Metal-Matic produces tubing for various applications such as automotive, appliance and construction. It has two other locations, Bedford Park in suburban Chicago, and Middletown, north of Cincinnati.