A 53-year-old woman was found dead with severe burns inside a Bronx apartment building Sunday afternoon, police said.

She was found in the bathroom of an apartment on Webster Avenue in Claremont Village around 3:45 p.m., police said. She was pronounced dead at the scene.

It is unclear how the woman, who has not been identified yet, caught on fire, police said. The building itself was not on fire, they said. The FDNY will determine the cause of the fire.

She was found by her boyfriend and his son, police said. Neither was injured.

The incident is under investigation.