Firefighters got an assist from Mother Nature to get the upper hand on Southern California fires. Light rain fell yesterday during a 1,400 acre blaze in the Tejon Pass near Gorman. That fire was contained. A 113 acre fire in the Angeles National Forest´s Big Tujunga Canyon was 90% contained. In the San Bernardino National Forest 50 miles east of Los Angeles, an arson-caused fire that burned across 6,800 acres was 95% contained. Investigators concluded that the fire, which shut down Interstate 15 for much of Monday, was caused by arson because it erupted in several different spots along the highway.