ALTURAS, Calif. — A firefighter killed by a wildfire in Northern California was scouting the area when he became trapped after erratic winds stoked the blaze, officials said Saturday. U.S. Forest Service firefighter David Ruhl was driving down a Modoc National Forest road in a vehicle Thursday. The fire suddenly grew and trapped him, information officer Ken Sandusky said. “He was trying to develop a plan of attack,” Sandusky said. Ruhl, of Rapid City, South Dakota, had been on temporary assignment since June in California, where he was an assistant fire management officer for the Big Valley Ranger District of the Modoc National. Scott Jacobson, a co-worker and spokesman for the Black Hills National Forest in South Dakota, said Ruhl, 38, volunteered to work in California.