Nearly eight months after the Consumer Product Safety Commission recalled more than 500,000 “hoverboard” scooters from eight manufacturers over fire hazards posed by the devices’ lithium-ion battery backs, the agency has opened an investigation into a fire that killed a 3-year-old girl in Pennsylvania on Friday.

A CPSC spokesman Tweeted over the weekend that the agency is working to open a federal investigation into the fire, which authorities say occurred shortly before 8 p.m. Friday night in Harrisburg, PA, when a hoverboard plugged into an outlet caught fire.

Fox43 reports that the 3-year-old girl was airlifted to a hospital and died early Saturday afternoon from complications of severe burns sustained in the fire. The incident began on the first floor of the row house and when authorities arrived they encountered heavy smoke and flames.

“They heard some sizzling and crackling in the hoverboard, and shortly thereafter, it exploded in flames,” fire Chief Brian Enterline tells PennLive.

Four other occupants were taken to area hospitals, where two remain in critical condition and two others were treated and released.

While local fire officials have ruled the fire accidental and attributed it to the overboard, it is unclear what model the device is and if it had been included in the CPSC’s previous recall for the scooters.

Fire chief Enterline tells PennLive that hoverboards are “notorious for starting fires,” and warned residents to stop using the devices.

“We’ve seen too many fires and too many fire fatalities as a result of these hoverboards,” he said.

In addition to announcing that an investigation was imminent the CPSC spokesperson also Tweeted a reminder of last year’s recall, which was initiated after several exploding hoverboard incidents.

At the time of the July 2016 recall, there had been at least 99 incidents reported to the CPSC of the battery packs in self-balancing scooters/hoverboards overheating, sparking, smoking, catching fire and/or exploding including reports of burn injuries and property damage.

Elliot Kaye, who was Chairman of CPSC at the time of the recall, said the Commission had investigated more than 60 hoverboard fires in more than 20 states that resulted in more than $2 million in property damage.

“Let me be clear about this — all of the hoverboard models included in this recall were made with fundamental design flaws that put people at real risk,” Kaye said in a statement in July. “My message to the public was clear in February and continues to be clear today: Do not use a hoverboard that does not meet UL’s electrical safety requirements for these products.”

Issues with the boards began around the 2015 holiday season when many who received the devices as gifts reported they had caught fire or exploded while being plugged in to charge.

In January, the CPSC announced it was investigating 13 hoverboard companies. Engineers with the agency tested hoverboards – both new models and those involved in fire incidents – at its National Product Testing and Evaluation Center.

A month later, the agency said that over a two-month period it had received reports from consumers in 24 states of self-balancing scooter fires, including the destruction of two homes and an automobile.

The agency then notified retailers, manufacturers, and importers that self-balancing scooters are not safe unless they meet certain standards set by the Underwriters Laboratory. Shortly after that, retailers, including Amazon, Target, and Toys ‘R Us, began removing the devices from their physical and online shelves.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.