Twelve people were injured, two seriously, in an explosion and fire at a Maryland apartment building on Wednesday and the residents of one unit have not been identified, a fire official said.
Fire crews responded to the garden apartment complex on Quince Orchard Boulevard in Gaithersburg around 8:40 a.m. for an explosion in the building and a fire with a partial collapse, Montgomery County Fire Chief Scott Goldstein said. in a press conference. Maintenance staff used a ladder to rescue two people from the building, including a person on a rear balcony, Goldstein said.
Two people were treated at the scene and 10 others were taken to hospitals, including two adults in critical condition, Goldstein said. The remaining eight, including four children, were taken to hospitals with mild to moderate injuries.

Most of the occupants of the two directly affected buildings have been contacted and accounted for, but officials have been unable to reach residents of one unit, Goldstein said.
Other buildings in the surrounding areas have been checked and there are no concerns about gas in those buildings for residents who can re-occupy their homes on Wednesday night, he said.
By mid-morning, firefighters had put out the fire and a gas-fueled fire raged in the building until gas service was shut off, he said.
People told investigators at the scene that there was a smell of gas Wednesday morning, but Goldstein said there were no 911 calls reporting a gas leak before the explosion. The last gas-related call at one of the affected buildings was in late September, he said.