FDNY officials confirm fatal Harlem fire was caused by lithium-ion battery

At least one person is dead, and 17 people were injured after a fire broke out inside a 6-story apartment building in Harlem on Friday.

FDNY officials confirmed Saturday that the cause of the devastating fire was a lithium-ion battery. 

Before the cause of the fire was determined, FOX 5 NY reported seeing e-bikes and their batteries being pulled from the building. 

The fire began inside a third-floor apartment at around 2:15 p.m. and quickly spread, trapping unprepared residents above the flames.

Witnesses said they saw one person jump out of the burning residential building on St. Nicholas Place and 149th Street. This person's condition is unknown., 

Video shows victims attempt to escape a fire in Harlem Friday.

"They were on the window sill, and they were trying to escape, but it's all the way on the top floor … they were hanging onto the window. I guess they couldn't hang on for long, and they fell to the ground," witness Michelle Paradis told FOX 5 NY.

Fire officials say that when they arrived on the scene, they found hallways full of smoke and fire while people laid unconscious inside apartments.

Firefighters were forced to do rope rescues to save some of the people from the building.