(IDEX Online) - A security guard at a jewelry store was shot dead yesterday during a heist at a shopping mall in Illinois, USA.Surveillance video shows three raiders step round the 57-year-old man as he laying bleeding on the floor.Police officers who happened to be on a training exercise at the mall property gave him CPR but he died hours later in hospital.The crime happened at River Oaks Center (pictured), a shopping mall in south suburban Calumet City. The raiders smashed display cases with their weapons, stole jewelry and fled in under 60 seconds.An employee at a neigboring barber shop told the CBS2 news station he heard about 15 gunshots as his customers dropped the ground in fear.An 81-year-old man was was also injured in the incident, though not by gunfire.