(IDEX Online) - Raiders smashed showcases with sledgehammers at a jewelry store in California, USA, and fled with $900,000 of jewelry in garbage cans.The Jewelers' Security Alliance (JSA) said it was just one of 14 smash and grab attacks in the southern part of the state within a month.It warned that such robberies were at "crisis level" and urged retailers to take precautions - and not to challenge raiders under any circumstances.Three men in black masks and clothing struck at Jewels by Alan, in Irvine, on 31 July.The owner, two customers and other staff members took cover on the floor to protect themselves from flying glass.JSA said: "Do not resist in a smash and grab robbery. In addition to sledgehammers and other dangerous tools, the suspects may be armed with guns and knives. Stay out of their way!"Pic courtesy Irvine Police Department.