A 7-year-old boy and a teenager were killed in a fire sparked by an e-bike's lithium-ion battery in New York on Monday, marking the city's fifth death in connection with the batteries this year, officials said.
Calling the incident a "terrible tragedy," New York City Fire Chief John Hodgens said the blaze started in the vestibule of the first floor of a residential building in Queens.
The blaze quickly traveled upstairs, where a man and his children were staying, NBC New York reported. Four people were able to jump out of windows, but two did not survive, Hodgens said on social media.
"The way these fires occur, it’s like an explosion of fire. The occupants have very little chance of escaping," Hodgens said.
"We have been talking about this for a couple of years and how dangerous it is to store these devices anywhere near your exit. This bike was right at the front door of the house and the occupants didn’t have a chance to get out of the building,” he said.
The number of fires caused by lithium batteries across the U.S. is rising.
Monday's blaze marked the city's 59th fire and fifth death caused by lithium-ion batteries this year, said Dan Flynn, the fire department's chief fire marshal.
Last month, a lithium-ion battery sparked another fast-moving fire in New York City, leveling a supermarket and a neighboring laundromat.
Authorities said an electric mobility device, possibly an e-bike powered by a lithium-ion battery, was to blame for the five-alarm fire.
E-bikes are widely used in high-density cities, especially in New York, where they are popular for delivery services. The lithium-ion batteries that power them have become increasingly common in transportation, as well as in household products and residential solar energy systems.
When the batteries fail or overheat, however, they can release flammable, toxic gases that can spark fast-spreading fires that are difficult to extinguish.
“The source of the gases that are creating the flames is confined within a cell battery that will not allow water in,” Ofodike Ezekoye, a fire scientist and professor of mechanical engineering at the University of Texas at Austin, has said. “When firefighters are responding to these types of incidents, it takes a lot longer to be able to control the fire, because it requires so much more water.”
As the number of fires caused by lithium batteries rises across the country, firefighters and other experts have warned that the training needed to fight them is lagging in many places, while many users also may not be aware of the risks.
"We want people to use them, but we want people to use them safely," Flynn said after Monday's fire.
He warned that e-bike riders should buy chargers that are compatible with their devices.
"Do not buy the cheapest device. We lost two people today; we were fortunate not to lose six," he said.