Police are investigating after a man was found dead in a storm drain Tuesday morning in midtown Manhattan, authorities said. 

The body was discovered about 11:40 a.m. near East 33rd Street and First Avenue, police said. Responding officers found an unconscious 49-year-old man inside a storm drain and EMS pronounced him dead at the scene. Authorities have yet to release the man's identity. 

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NYPD sources told the New York Post that the body was uncovered during a routine inspection by the Department of Environmental Protection at a site that is part of a hospital expansion project. NYU Langone Medical Center is located near where the body was found. 

According to the Post, the body had been dead for a long time. The medical examiner is determining the cause of death.