A three-alarm fire in Jersey City on Wednesday injured four residents and a firefighter and displaced multiple families, authorities said.

The Jersey City Fire Department responded at about 1:30 p.m. to a reported fire at 154 Summit Ave. Upon arrival, firefighters encountered a working fire and began rescue operations inside the building.

Firefighters rescued three people while working to contain the flames. Two of those were removed from a second-floor window onto a porch roof and then brought to safety using a ladder, officials said.

Four residents were taken to a hospital with nonfatal injuries. Firefighters also rescued a cat and a dog from the building.

During the response, a fire captain fell and struck his head and was taken to a hospital, officials said.

The fire was contained to the single building. Authorities said it appears to have started in a car parked a few feet from the structure.

Nine adults and two children were displaced and are receiving emergency assistance from the Red Cross.