An explosion and fire hit the Quaker Oats plant in downtown Cedar Rapids, Iowa, on Saturday, Oct. 24. Nobody was hurt.

Police and firefighters were sent to the back of the building at about 4:45 p.m. Central time after a reported explosion.

Crews found heavy smoke and flames on the north side of the building, along with what appeared to be evidence of an explosion.

The city said all plant workers were accounted for by 5:30 p.m. No employees or firefighters were injured.

Mayor Tiffany O'Donnell said the blast hit a back area where product moves and where people usually aren't working.

A large plume of dark smoke rose over the area, and traffic backed up on Interstate 380 near the S-curve.

The fire was declared under control early Saturday evening. Local reports put that at 5:55 p.m. or 6:15 p.m.

Cedar Rapids committed all its available resources. Help came from Marion, Hiawatha and Linn County, plus Area Ambulance Service.

PepsiCo owns the plant. A PepsiCo Foods US spokesperson said details of how the fire started will be investigated.

Officials have not announced a cause. They also have not said how badly the plant was damaged or whether production will be affected.

The Quaker website calls it the largest milling facility in the world, processing more than 2 million pounds of oats a day.

Read the full article for the timeline and PepsiCo's statement on the Cedar Rapids fire.