Officers responded to a report of a man down in the 28000 block of Rochelle Avenue at around 12:10 a.m., according to the Hayward Police Department. A 56-year-old man was found suffering injuries from unknown means.
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The victim was taken to St. Rose Hospital where he was pronounced dead, police reported. Officials did not release the man's identity.
The Alameda County coroner's bureau is scheduled to perform an autopsy today, according to police. There were no known suspects.
Anyone with information that might help the investigation is asked to contact the Hayward Police Department Criminal Investigations Bureau at (510) 293-7034.