JERSEY CITY, N.J. (PIX11) — A fast-moving fire in Jersey City temporarily trapped four people inside and caused part of the building to start collapsing as firefighters rushed in.

The fire happened on Randolph Avenue and McDougall Street Monday late morning.

A battalion chief on the scene said he was hopeful the two people pulled from the fire unresponsive will pull through after being overcome by thick, black smoke.

Sonia Garretson said she was on the second floor working as a home health assistant for a woman in a wheelchair when the fire began. She immediately knew she could not get her patient out by herself.

“I was scared, called 911 and went outside looking for help,” Garretson said.

Jimmy Cortez was walking to work when he noticed the commotion. He said he ran in and found the woman in a wheelchair upstairs. However, he and another man quickly became overwhelmed by the smoke as they struggled to move her down the stairs and through the door. Cortez got pinned under the wheelchair.

“The fire department came right on time,” Cortez said.

The woman in the wheelchair and another woman were transported to the hospital unresponsive and in serious condition, according to the Jersey City Fire Department.

“Heavy fire on the second floor, and the whole rear was involved: basement, first and second floor,” said Deputy Chief William McClintock.

McClintock said his firefighters also pulled out two dogs — one did not make it.

The cause of the fire, including why it spread so quickly, is still under investigation. At one point the flames were so intense that the back of the home buckled and firefighters had to back off for risk of collapse, McClintock said.

At least seven people were displaced by this fire, according to the Jersey City Fire Department. The Red Cross is assisting some of them.