(IDEX Online) - Thieves who broke into an unattended Brink's security trailer in Southern California, USA, may have escaped with up to $150m in jewelry, gems, high-end watches, according to exhibitors.The vehicle was on its way from the International Gem and Jewelry Show in San Mateo, south of San Francisco, to an event at the Pasadena Convention Center, northeast of Los Angeles. Guards who had pulled over at a rest stop reported the lock had been tampered with at 2am on 11 July.Brink's reported the total value of the stolen items at $10m, but Arnold Duke, president of the San Mateo event, said exhibitors routinely underinsured goods because of high premiums and their trust in Brink's. "It's such a tragic situation," he told news outlets. Many of the victims are said to be mom-and-pop operators who have lost their entire livelihoods.Brink's said in a statement: "We are working with law enforcement and we will fully reimburse our customers for the value of their assets that were stolen, in accordance with the terms of our contract."File pic of a Brink's van