A child died after a "tragic accident" involving a Peloton treadmill, according to a message from the company's chief executive sent to owners of its Tread+ exercise equipment, reports said Friday.

"I'm reaching out to you...because I recently learned about a tragic accident involving a child and the Tread+, resulting in, unthinkably, a death," The Wall Street Journal quoted chief executive John Foley as saying in a letter.

Foley advised users to keep Peloton treadmills out of reach of children.

He didn't provide further details about the accident, but added the company was "aware of only a small handful of incidents involving the Tread+" where children had been injured.

He said Peloton designed and manufactured all its products "with safety in mind." The 132-kilogram Tread+, made mostly of carbon steel, starts at $4,295.

The Consumer Products Safety Commission, the federal agency overseeing the protection of U.S. consumers from dangerous products, said it was aware of the incident and investigating.

Peloton sells cycling equipment and treadmills that can be connected to online fitness classes. Its business boomed as people sought alternatives to stay in shape as gyms closed down during the pandemic.

According to the commission, hospitals treated 68,296 injuries from accidents involving exercise machines in 2019, Forbes reported.

Between 2018 and 2020, the commission received reports of 17 deaths linked to the use of a treadmill - including one involving a 5-year-old, according to BBC News.