Sig Alert, 15 Freeway, Ontario 6:14 a.m.
A tractor trailer broke down on the southbound 15 Freeway, snarling traffic for miles.
The California Highway Patrol issued a Sig-Alert at 6:14 a.m. after the semi stopped in the middle of the freeway south of Jurupa Street. By 7 a.m., traffic had backed up to at least the 10 Freeway. Workers were unable to move the tractor trailer immediately because its back brakes had locked up. The Sig Alert was canceled at 7:36 a.m.