Police are investigating after a man was found dead on a downtown sidewalk outside a parkade early Wednesday morning.

A passerby called police at about 5:30 a.m. after seeing a body on the sidewalk at Second Street and 10th Avenue S.W., police say.

A man, believed to be in his 30s, was declared dead at the scene.

Police are asking the public to stay away from 10th Avenue between Fourth Street and First Street while they investigate.

The City Centre Parkade will be closed all day, a Calgary Parking Authority spokesperson said.

Police say it's not yet clear if the death is suspicious. The medical examiner's office is assisting in the investigation.

Anyone who has information about the incident is asked to call police or contact Crime Stoppers.

10 ave sw is closed between 1st and 4 st sw due to ongoing incident please avoid the area if possible <a href="https://twitter.com/hashtag/yyc?src=hash">#yyc</a> <a href="https://twitter.com/hashtag/yyctraffic?src=hash">#yyctraffic</a> —@CalgaryPolice

The City Centre Parkade will be closed all day Wednesday while police investigate the death of a man who was found on 10th Avenue S.W. outside the structure. (Dave Gilson/CBC)