A woman in her 20s was found dead in a Brooklyn park Thursday morning, authorities said.

An off-duty FDNY firefighter who was jogging in Owl’s Head Park in Bay Ridge found the woman in a skate park at about 9 a.m. and called 911, authorities said.

She appeared to have blunt-force trauma to the head and was fully clothed when found around 67th Street and Colonial Road, authorities said. Her identity wasn’t immediately released.

Police were investigating the death as suspicious.