LOS ANGELES—Union Pacific crews worked to clear tracks after a train derailment on Jan. 15 in Lincoln Heights, near an area where thousands of empty boxes were left behind by cargo thieves. “At this time, there is no estimated time for completion and the cause remains under investigation,” Union Pacific spokeswoman Robynn Tysver told City News Service. “No one was injured.” The derailment occurred around 4 p.m. Saturday at the intersection of San Pablo Street and Valley Boulevard, which was then blocked indefinitely, according to USC, which has its Health Science Campus nearby. A total of 17 cars derailed, Union Pacific told KTLA. The area has been plagued by thefts of cargo in recent days, and video from the scene showed the ground littered with empty boxes from companies such as UPS and Amazon. Union Pacific has asked the L.A. County District’s Attorney’s Office to prosecute anyone arrested for the …