(CNN)An explosion that wrought "catastrophic damage" Thursday to a garden-style four-story building in Silver Spring, Maryland, has left over a dozen injured, five seriously, a Montgomery County Fire Department public information officer said.
Over a dozen injured, 5 seriously, in a Maryland residential building fire, explosion, officials say
Firefighters immediately made several rescues, said spokesperson Pete Piringer. All priority-one patients have been transported or are in transit to a hospital, he said.
"I think there were people we were looking for and I think they've been accounted for," said Piringer. "Again, that's preliminary, but we did make several rescues."
The fire department was called in for an explosion at the apartment around 10:30 a.m., Piringer said. Firefighters encountered heavy fire, he said.
Piringer said the four-story apartment building, which had between 12 and 18 units, sustained heavy structural damage. Though the fire has been contained, fire personnel have evacuated nearby buildings.
There are currently over 100 firefighters on the scene and none have suffered injuries, Piringer said.
The root cause of the explosion is unknown, Piringer added.
This is a developing story and will be updated.