A security guard was killed and a shotgun-armed suspect was critically wounded outside a Compton supermarket, Los Angeles County sheriff's officers reported. Deputies said the 35-year-old guard, whose name was withheld pending notification of relatives, attempted to halt Adin Hernandez, 25, of Compton, who ran past him and two other employees of the market at 4410 E. Compton Blvd. The security guard and Hernandez reportedly fired simultaneously. Hernandez was struck in the chest and taken to Memorial Hospital of Long Beach. Neither of the other two store employees was struck.