UPDATE: The highway is back open.
UPDATE (7:53 a.m.) - The left lane of the highway is expected to reopen at approximately 8:15 a.m.
(6:51 a.m.) - The northbound lanes of Highway 101 were closed just north of Padaro Lane in Summerland early Thursday morning because of a semi-truck fire.
The incident was first reported at 5 a.m.
Caltrans says there is no estimated time for re-opening of the highway.