Man found dead in Chicago alley on NW Side: police

CHICAGO - Chicago police launched a death investigation after a person was found dead in an alley near Portage Park Saturday night. 

An unidentified man was found unresponsive in an alley in the 5800 block of West Belmont Avenue at 11 p.m.

He was pronounced dead on scene. 

The cause of death is under investigation. No further details were available.