A billowing fire engulfed a three-story building near downtown Minneapolis on Wednesday morning, sending 13 people to hospitals with injuries ranging from burns to trauma associated with falls.
Officials said six of those injuries were critical, but no fatalities were reported.
An explosion was reported about 8:15 a.m., and within minutes a fire raged through the building, said Robert Ball, a spokesman for Hennepin County Emergency Medical Services. Paramedics responded to find victims on the ground, some with injuries that suggested they may have fallen multiple stories.
"It's not clear whether people were pushed out of the building from the explosion or whether they fell or jumped out of windows to escape," he said.
Authorities weren't sure whether any residents were still inside. Assistant Minneapolis Fire Chief Cherie Penn said the roof had partially collapsed, and it was too dangerous for firefighters to enter and sweep the premises.
Penn said 13 people were taken to local hospitals, and six were considered to be critically hurt. Ball said it was too early to determine what caused the explosion or fire.
Plumes of thick, whitish-gray smoke could be seen rising from the building, which has a grocery store on the ground floor and two levels of apartments above it. Flames could be seen through third-story windows, and the frigid air was filled was the acrid smell of smoke.
Abdikadir Mohamed, whose uncle owns the grocery store, watched the scene in silence, struggling to put his thoughts into words.
"This is bad," he said.
Firefighting efforts were being hampered by the sub-zero temperatures. As firefighters aimed their hoses at the flames, water gushed from windows and doorways, forming icicles on window frames and leaving the street slick and icy.
The facade of the building and trees out front were also coated with a layer of ice.
Ball said the frosty conditions were creating an additional set of hazards for the 55 firefighters on the scene.
"While heat-related illnesses are common for firefighters, now you combine that with the rapid onset of frostbite or hypothermia when they come out and they're wet and exposed to bitter cold temperatures," he said.
Fire officials appeared to get the fire under control about 11:30 a.m. Firefighters who had been aiming a hose at the flames from a truck-mounted crane shut off their water, and with smoke still billowing from the roof, other investigators began to approach the front door.
Outgoing Minneapolis Mayor R.T. Rybak told reporters he was "deeply concerned" about the fire.
"I'm also deeply grateful for the firefighters and other crews who came out here and kept it from getting worse," he said.
A mosque that is next door to the gutted building appeared to escape any obvious structural damage. Abdisalam Adam, the imam at Islamic Civic Society of America & Masjid Dar Al-Hijrah, watched the firefighting efforts and said he was praying for those affected by the fire.
"It's devastating and very sad," he said.
As many as a dozen people have been injured in a building explosion in Minneapolis, NBC affiliate KARE reported.
First responders are on the scene of 514 Cedar Avenue South, near Interstate 94 in in the city's Cedar-Riverside neighborhood.
KARE is reporting that injuries include burns and trauma suffered by people falling or jumping from windows.