SAN DIEGO (FOX 5/KUSI) -- A man was found dead behind a grocery store in the Mission Valley East area Thursday morning, according to the San Diego Police Department. After the department's communication center received a call regarding an unconscious male around 7:26 a.m., officers responded to the east side of the Food 4 Less grocery store at 7730 Hazard Center Drive. Local leaders share resources for victims of hate Despite life-saving efforts by the officers and accompanying medics, the man did not survive, according to SDPD. The man was described as a 25-year-old man, but his name is being withheld pending family notifications. The death was initially believed to be caused by an overdose based on items found at the scene. After further investigation, officers had enough information to believe the man had been assaulted and called homicide detectives to the scene, the release said. Next steps include working with the San Diego County Medical Examiner's Office to determine the man's injuries and the exact cause of his death, SDPD said. Detectives are still examining evidence from the scene and looking for surveillance footage. Anyone with additional information is encouraged to contact SDPD's Homicide Unit at 619-531-2293 or Crime Stoppers at 888-580-8477.