SAN DIEGO (KABC) -- The death of a Navy SEAL trainee who died during an exercise in Coronado in May has been ruled a homicide.According to the San Diego County autopsy report released Wednesday, Seaman James Derek Lovelace's official cause of death is drowning. The report also states that an enlarged heart could have been a contributing factor.The term "homicide" does not necessarily mean a crime was committed. The instructor involved in the death has not been charged.The Navy says Lovelace was treading water during a swimming exercise May 6 wearing fatigues, boots and a dive mask as instructors splashed and dunked him.The autopsy report stated that multiple witnesses said Lovelace was struggling during the training exercise, and his face was purple and lips were blue.After struggling, he was pulled from the water and rushed to a civilian hospital, where he died."It is our opinion that the actions, and inactions, of the instructors and other individuals involved were excessive and directly contributed to the death," the autopsy report stated, in part.The Naval Criminal Investigative Service (NCIS) released the following statement regarding the coroner's report.Lovelace had joined the Navy about six months before his death.