The Brief One person was killed late Thursday night after a minivan slammed into a Caltrans truck at high speeds on the southbound 405 Freeway in Irvine. The crash occurred near the MacArthur Boulevard on-ramp, prompting a several-hour closure of the transition road from the southbound 55 Freeway. A high-speed collision involving a minivan and a Caltrans vehicle left one person dead late Thursday night, triggering a major investigation and an hours-long closure of the 405 Freeway in Irvine. What we know:The crash happened just after 10:40 p.m. on the southbound 405 Freeway at the MacArthur Boulevard on-ramp, according to the California Highway Patrol. A SigAlert was issued shortly after the incident, closing the transition road from the southbound 55 Freeway to the southbound 405 for several hours while investigators processed the scene.