Sig Alert, 40 Freeway, Ludlow 5:37 a.m.

A tractor trailer overturned on the 40 Freeway, spilling boxes, blocking all lanes and prompting a Sig Alert. The semi rolled over on the westbound 40 about five miles west of Ludlow at 5:37 a.m., the California Highway Patrol said. CHP officers issued a Sig Alert at 5:45 a.m. The duration was unknown. UPDATE: The Sig Alert was canceled at 8:02 a.m.