Engineer Larry DuBoise keeps his left hand near the emergency brake as he scans the tracks for people or vehicles in the path of his 400-ton commuter train.

Hurtling by strawberry and sod fields, industrial parks or residential neighborhoods at almost 80 mph, DuBoise would need more than a quarter-mile to bring the mass of steel to a stop. So his eyes never leave the tracks and his hand never strays."It's a very helpless feeling when you see them and you put it in emergency and you can't do anything else," says DuBoise, who has struck and killed one person and injured two others in his 22 years as an engineer.

Twenty-five people have been killed by Metrolink trains since the Los Angeles area commuter line began service in October 1992. Thirteen have died this year - seven in the last two weeks.

Four people, including a pregnant woman, were killed Wednesday night when a train traveling 63 mph rammed a car at a crossing in Riverside, 50 miles east of downtown Los Angeles. A 7-year-old girl, her mother and her grandfather died Aug. 15 as they took a shortcut across tracks in Glendale, 10 miles north of the commuter's downtown hub.

Media accounts of such accidents customarily focus on the dead and their mourning survivors. But DuBoise and others on the rails say people fail to appreciate the emotional toll such deaths take on engineers.

"They're really victims, too, because they have to live with this the rest of their lives," says Dawn Soper of Operation Lifesaver, a nonprofit organization based in Alexandria, Va., that promotes railroad safety.

Many are haunted by images of mangled wreckage and lifeless bodies. Others remember the victims' terror-filled eyes just before impact.

"When a train hits a body . . . the gore is terrifying," says Chris Knapton, spokesman for Metra, the Chicago area's commuter line, which has recorded 13 fatalities this year.

DuBoise, who pilots the daily 6:21 a.m. Metrolink from Oxnard to Los Angeles, says some of his colleagues have taken up to six months off to recover from the trauma of hitting someone.

"It'll always be with you," he tells a reporter.

Phil Nerkowksi, an engineer and Metrolink supervisor, says each individual decides how much time to take off. The company provides psychological counseling if it's requested.

"We keep touching bases with them to make sure they're all right," says Nerkowski, 38, who acknowledges six fatal accidents in his train-driving career but declines to talk further about them.