Just weeks after its celebrated launch, the Samsung Galaxy Note7 is on fire–literally. On Friday, the company announced that due to a “battery cell issue,” it would recall and replace all phones sold, and stop sales of the device worldwide–in what some are calling the highest profile consumer tech recall in recent memory.

Since the Note product line is so popular with business professionals, we break down the facts you need to know about the recall.

SEE: Samsung Galaxy Note7: The smart person’s guide

What happened?

Multiple reports from South Korean social media accounts showed Note7 phones that had a battery that “exploded” while plugged into a charger. Koh Dong-jin, head of Samsung’s smartphone business, said in a press conference Friday the fires were caused by faulty battery cells.

Samsung has manufactured 2.5 million Galaxy Note7 devices so far, and sold 1 million, Koh said. As of Friday, 35 cases of the battery issue globally were reported to the South Korean company. Samsung said in a statement that it is “currently conducting a thorough inspection with our suppliers to identify possible affected batteries in the market.”

At the press conference, Samsung officials estimated that the problem affects only 24 in 1 million devices–roughly one for every 42,000 sold. There are no reports of injuries.

Why did it happen?

“There was a tiny problem in the manufacturing process, so it was very difficult to figure out,” Koh said at the press conference. “It will cost us so much it makes my heart ache. Nevertheless, the reason we made this decision is because what is most important is customer safety.”

The problem seems to be with the batteries themselves, rather than power adapters or circuitry, according to an anonymous Samsung official quoted by South Korea’s Yonhap News Agency. “Products installed with the problematic battery account for less than 0.1 percent of the entire volume sold,” the official said. “The problem can be simply resolved by changing the battery, but we’ll come up with convincing measures for our consumers.”

The only country not affected by the recall and sales halt is China: Samsung said it used a battery made by a different supplier for the devices sold there, according to the Associated Press.

In a Galaxy Note7 teardown from iFixit, it appeared that the lithium-ion battery inside the phone was made by Samsung. However, Samsung officials said in the press conference that the company works with several suppliers to manufacture the batteries for the device.

This recall will be costly due to the fact that the device has a non-removable battery, which requires Samsung to replace the entire phone, said TechRepublic managing editor Bill Detwiler, who regularly cracks open devices for TechRepublic and CNET.

“Integrated batteries let phone manufacturers build sleeker and often more water-resistant handsets, but Samsung’s recall illustrates their one major drawback,” Detwiler said. “If the battery is defective, there’s no easy way to replace it.”

SEE: Photos: Samsung Galaxy Note7 smartphone

What’s next?

The company has yet to say how it plans to issue the replacement phones. At the press conference, officials said it will take about two weeks to organize the replacement program.

This isn’t Samsung’s first recall: In 2014, it recalled its Galaxy S5 smartphones after a camera malfunction in a small number of devices. At that time, the company advised customers to get in touch with their carrier or Samsung itself for a replacement.

Last year, Apple recalled its Beats Pill XL wireless speaker, after rare cases when its battery overheated and caused a fire risk. The company asked those who purchased the speakers to fill out a web form, and then sent them a postage paid box to return the speaker. After Apple received it, the user received either Apple Store credit or an electronic payment within 3 weeks.

The well-reviewed Galaxy Note7 was one of Samsung’s brightest hopes after several years of weakening mobile sales. The timing couldn’t be worse with Apple’s new iPhone announcement expected next week.