HAYWARD -- Authorities are investigating what caused the death of a man whose body was found in the front yard of a home on Christmas morning. Officers responded to a 3 a.m. call from a person who lived in a home on the 24000 block of Silva Avenue who found an unresponsive man on a couch in his front yard, Sgt. Eric Melendez said.

Paramedics responded to the home but were unable to revive the man. The victim -- a 56-year-old transient known to frequent Hayward -- was pronounced dead at the scene.

The man's name is being withheld pending his official identification by the Alameda County Coroner's bureau.

The man's cause of death remained under investigation late Thursday morning, but Melendez said there appears to be no evidence of foul play. He also said the man often slept on the couch in the resident's front yard and that he might have died as a result of a medical issue.

An autopsy is set for Friday and will reveal how the man died, Melendez said.

No additional details were released.

Anyone with information about this case is asked to call police at 510-293-7000.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.