SAN DIEGO (CNS/CBS 8) - A catalytic converter sparked a several-acre brush fire alongside Interstate 5 in the Torrey Pines area, forcing a complete closure of a stretch of the freeway for nearly an hour Monday afternoon.

The blaze began spreading about 12:45 p.m. on the west side of the regional route, between Genesee Avenue and Sorrento Valley Road, according to the San Diego Fire-Rescue Department.

Due to thick smoke that severely limited driving visibility in the area, the California Highway Patrol closed down the interstate completely between Interstate 805 and Genesee.

It took ground crews and personnel aboard a water-dropping helicopter about a half-hour to gain control over the fire, which scorched roughly two acres, SDFRD spokesman Maurice Luque said.

The CHP reopened all northbound freeway lanes in the area about 1:50 p.m. and all but two of the southbound ones roughly an hour later.