A 36-year-old man was found dead Tuesday at the bottom of a stairway outside of a home in Brooklyn, police said.

The dead man, whose identity wasn’t immediately released, was discovered when a passer-by saw him at the bottom of the stairs leading to the basement at 318 Union Avenue in Carroll Gardens around 4 p.m. The man had severe head and neck trauma, cops said.

The medical examiner is investigating and will determine the cause of death.