Update: Police lift evacuation order, reveal cause of massive welding plant fire in Pittsfield Township

PITTSFIELD TOWNSHIP, MI - Authorities evacuated homes and briefly shut down highways surrounding a large fire at an Ann Arbor-area welding business Thursday afternoon.

Firefighters were on scene about 12:40 p.m. April 11 at Ann Arbor Welding Supply, 4811 Carpenter Road in Pittsfield Township, said Director of Public Safety Matt Harshberger.

Explosions could be heard miles away and a large plume of black smoke could be seen drifting above an overpass that was shut down as police and firefighters responded.

Huron Valley Ambulance spokesperson Matt Rose said shortly after 2 p.m. that no one had been treated for any injuries related to the fire. HVA’s medical hazardous materials team was standing by to assist fire agencies if needed.

Officials asked that the public avoid the area of Carpenter Road and Morgan Road for the next several hours, according to a Nixle alert from the Washtenaw County Sheriff’s Office.

Paul Cyr, general manager of nearby True Green, helped evacuate people from the business Thursday after hearing loud explosions at the welding supply facility, about 150 yards away.

“We heard a big boom, like a car hit the building,” Cyr said. “We ran out front and saw that there were a couple of cylinders that were on fire in the back, and black smoke.”

Cyr said law enforcement officials moved him and others away from the business once the smoke and frequency of explosions increased.

Bryan Binert said he could see huge clouds of smoke from the expressway and later heard explosions from a nearby restaurant while he and his friend were out to lunch.

“We could hear the explosions from here – about 20 of them,” said Binert, 24, who lives a little more than a mile away from the business. “We could see the flames from here. Traffic was pretty backed up for a good minute, but it looks like they’ve got it under control.”

U.S. 23 was briefly shut down in both directions between Michigan Avenue and I-94 during the fire response, but was soon reopened.

Sheriff’s deputies were going door-to-door evacuating homes within a one-mile radius of the facility.

MLive photographer Tanya Moutzalias and reporters Martin Slagter and Dana Afana contributed to this report.