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 the odour of gas, said fire chief Kevin Dippolito.
Crews evacuated people from the building, and just 15 to 30 seconds after they left, a second explosion and fire occurred.
Authorities have suggested that the cause may be a gas leak, but the investigation is ongoing.
Local gas company PECO stated that their crews were responding to reports of a gas smell when the explosion happened and emphasized that it's not yet known if their gas or equipment was involved.
Images and videos from local media show the nursing home with significant damage and flames rising from the structure.
In recounting the rescue efforts, Mr Dippolito noted one police officer who heroically carried two people to safety.
Five individuals who were initially missing have since been accounted for.
Witnesses nearby described the sound of the explosion as a 'loud ka-boom' with one man comparing it to an airplane crash.
Family members of those in the nursing home expressed deep concern as they awaited updates. One woman expressed joy upon learning her sister was alive but still worried about her condition.
Pennsylvania's Governor Josh Shapiro commended the rapid response from local authorities and the community, highlighting the spirit of neighbors helping one another in times of need.
