HAMDEN, Conn. (WTNH) — An electric portable cooking burner on a second-floor deck that had been left on caused a huge fire early Saturday morning at an apartment complex in Hamden, according to fire officials.

The Hamden Fire Department said 21 units at the Town Walk Apartments on Town Walk Drive, near the Farmington Canal Trail, are now uninhabitable.

The American Red Cross is helping between 50 and 55 people with housing.

“There were 21 units affected and 21 families that were displaced,” Susan Shaw, the senior director of disaster services of the American Red Cross, said. “At this point, about 50-55 people.”

Authorities said the 9-1-1 call came in around 4:30 a.m.

Fire officials said 14 units in Building 27 suffered “considerable amounts” of fire, smoke, and water damage, and seven other units had light to moderate smoke damage. The roof and floors of the structure started to fail due to the building’s lightweight wood truss construction design, fire officials said.

“It was terrifying,” Elizabeth Fulton said. “I’ve never seen flames like that before. Lots of smoke, lots of flames.”

Dozens of families had to grab what they could and run out into the dark.

“As soon as we went out of the hallway down the stairs, you just felt the heat from the flames,” Derrick Way said. “My son said, ‘Daddy, look, fire, it’s a fire,’ and I’m like, this is real. I didn’t want to look back. I just wanted to get away as far as possible.”

Those displaced by the fire are now staying with family or in a local hotel. Way said he’s getting help from the Red Cross and the Town of Hamden.

The Hamden Fire Marshal’s Office and Connecticut State Police Fire and Explosion Investigation Unit determined an electric portable cooking burner on the second-floor deck had been left on, causing it to ignite nearby “combustibles” and spread to the wooden deck.

The Connecticut State Fire Prevention Code prohibits using and storing any type of grill or cooking device on decks, beneath overhangs, or within 10 feet of an apartment building, fire officials said.

The Keefe Center in Hamden accepts monetary donations for those who want to help families displaced by the fire.