Residents are demanding answers from their landlord after a carbon monoxide scare in their apartment building in Fordham.

Firefighters responded to the building on Decatur Avenue just after 6 p.m. Monday after residents called 911, saying they were not feeling well.

Fire officials say they found elevated levels of carbon monoxide inside. News 12 is told the boiler was leaking through the building and had to be shut off.

News 12 spoke with a resident coming home from the hospital, describing how she almost lost her daughters.

"I was at the hospital for a check up. When I got back home I found my four daughters and my sister fainted all over the floor. I grabbed my daughters to get help and they started to throw up."

MORE: Fordham apartment building residents, EMT members sent to hospital after carbon monoxide leak

Residents quickly evacuated and say they had working carbon monoxide alarms, but those weren't triggered by the gas.

The Department of Buildings has hit the property owner with a cease use order for the boiler. The owner is required to make repairs before the boiler can be turned back on.

Residents will have to deal with no heat or hot water as a result. 

“We shut down the boiler and vented the building and evacuated the building and all the CO levels are negative. We had a total of seven people that felt ill from high CO readings,” says FDNY Deputy Chief Michael Gunning.

News 12 is told four first responders were taken to the hospital for possible carbon monoxide poisoning. All of them are expected to be OK.