Two people have died and 20 others have been injured after two explosions and a fire at a Pennsylvania nursing home caused a partial collapse of the building.
Emergency crews were called to the Silver Lake Nursing Home in Bristol at about 14:00 local time (19:00 GMT) on Tuesday after receiving reports of an initial explosion and an odour of gas, said fire chief Kevin Dippolito.
Crews evacuated people from the building, and just 15 to 30 seconds after they left, the second explosion and fire occurred, Mr Dippolito added.
Authorities have suggested the cause could have been a gas leak, though their investigation is ongoing.
In a statement to US media, local gas firm PECO reported that the explosion occurred while its crews responded to reports of a gas smell, and it remains unclear whether its gas or equipment was involved.
Images and videos on social media show a partially collapsed building with flames billowing from it.
Mr Dippolito also described the rescue efforts, highlighting one police officer who managed to carry two people to safety towards medical staff.
Some individuals were trapped in the basement of the damaged structure but were successfully rescued, with five people initially unaccounted for later confirmed safe.
Witnesses nearby reported a loud "ka-boom," describing scenes of fire and chaos as they reacted to the catastrophe.
Concerned relatives awaited news about their loved ones, with one woman expressing her overwhelming relief upon learning her sister was safe.
Pennsylvania Governor Josh Shapiro commended the rapid response of local authorities and the selfless actions of neighbors during the crisis.
