A mother of four reportedly died after falling on a treadmill while exercising at a gym in Washington, United States on Friday.

Delrie Rosario, 36, fell and hit her head in what is being described as a “bizarre accident,” her sister Marissa Woods told a local news outlet.

Woods, who was working out with Rosario at the time of the incident, said Rosario had attempted to slow down the machine when she missed a step and collapsed, knocking her head on the treadmill.

“I was screaming, you know, ‘Anybody, just please help! Anybody know how to do CPR?’” Woods said.

She said some gym-goers came over after she yelled out for help, but she claims “not one worker” from the gym staff assisted. “I think they were in shock,” she added.

After hitting her head, Rosario did not regain consciousness and was transported to a nearby hospital, where she was pronounced dead, her sister said.

Treadmill deaths are rare, with only 30 reported deaths associated with the walking device from 2003 to 2012, USA Today previously reported based on figures from the US Consumer Product Safety Commission. But injuries are more common. In 2020, around 15,800 patients were treated in emergency rooms for injuries involving treadmills, The Washington Post reported, also citing the commission.

Rosario, who coined herself “the momma” on her Facebook page, was working two jobs to support her four children before her death, according to a GoFundme page that a local news outlet reports was set up by the woman’s co-workers.

Rosario’s heart, lungs, kidneys and liver have since been transplanted to save the lives of multiple people on organ donor waiting lists, Woods told the outlet.

“(She’s) saving lives. How big can your heart be to still be saving lives?” Woods said.

She added: “Just think, somebody’s walking around…with her big heart. They don’t even know what heart they’re about to get.”