Scooter lithium battery investigated as cause of 5

At least seven people have been injured in a five-alarm fire in the Bronx neighborhood of New York City thought to have been caused by a lithium-ion battery, according to fire officials.

A civilian and an emergency services worker were seriously injured, and five firefighters received minor injuries, the New York Fire Department told CNN Sunday.

Almost 200 firefighters have been fighting the fire, which started in the roof of the rear part of a single-level commercial building on Grand Concourse and 181st Street, according to the New York Police Department.

FDNY Commissioner Laura Kavanagh told reporters at the scene Sunday the cause of the fire was a lithium-ion battery, which powered a scooter.

Lithium-ion battery sparks apartment building fire

"In all of these fires, these lithium-ion fires, it is not a slow burn there's not a small amount of fire, it literally explodes," Kavanagh said. "It's a tremendous volume of fire as soon as it happens, and it's very difficult to extinguish and so it's particularly dangerous."

Kavanagh said firefighters arrived at the fire around 10.41 a.m., under four minutes after the first call. All seven of those injured in the blaze are considered stable, she said.

"We have been able to not have a loss of life today, but there is extraordinary damage. This entire building behind me is completely destroyed," Kavanagh said. "The roof is caved in, there's nothing left, and it is all because of this one single bike."

The commissioner said more investigation needed into why the bike burst into flames. She said it may have been using an illegal battery.

The scooter was parked inside the rear part of a grocery store. Officials said it's not yet known who owns the bike.

The worst fires in New York City history have something in common: Immigrant victims

The fire department tweeted video of the fire igniting. The footage appears to be taken from a security camera and shows someone responding to the blaze and shifting the scooter before the flames intensified.

New York City Mayor Eric Adams told Sunday's news conference: "Our real push is to inform the public that something as simple and seen as recreational can be extremely dangerous and can take the lives of innocent people. This is a real problem we are having in the city."

Adams added, "A simple battery operated scooter like this, people are leaving in their homes, they’re leaving in their place of businesses, they’re leaving in their restaurants, they leave it parked for the most part in places that really they should not be parked in."

"The video is chilling, when you see how fast this fire started and spread, it's just really going to give you a point of pause," Adams said. He advised the public to only use legal lithium-ion batteries and to not place lithium-ion battery devices inside the home.

Fire officials said the blaze has been mostly extinguished but "pockets of fire" remain. Firefighters will stay on site through the night to make sure the fire doesn't escalate.

On Friday, Kavanagh said there had been more than 400 fires caused by lithium-ion batteries in New York City in the past four years.

In an opinion piece for a local website, Kavanagh said: "These fires start quickly, grow rapidly, offer little time to escape, consume everything in their path, and are very difficult to extinguish."

CNN's Susannah Cullinane contributed to this report.