LIVERMORE, Calif. (KGO) -- A driver was killed when an incoming ACE train hit his car Monday morning in Livermore.It happened just before 8 a.m. at a railroad crossing that is about a quarter-of-a-mile from the Livermore ACE Train station.Officials say it's early in this investigation, so they still don't have a clear picture of what happened. But according to witnesses, the car appeared to have been in the railroad crossing when it was hit."We heard somewhat of a loud boom," explained Joseph Pineda, who lives across from the intersection. "I didn't think it was anything because the train is pretty loud. But a couple of minutes (later), as we walked out, we heard the police and sirens. And obviously, we saw the car against the pole right there."According to Brian Schmidt, Director of Operations for ACE Train, investigators are still trying to figure where the car was hit. But he says, if the investigation finds that the driver was in railroad crossing after the crossing arms came down, it would have been difficult for the train to stop."It normally takes a passenger train anywhere from half-a-mile to three-quarters-of-a-mile to stop, depending on how fast they are going," says Schmidt, adding that the train was likely already slowing down as it approached the station.He says trains travel about 45 mph, but speeds could be higher in areas where the train is traveling a straight section of tracks.Justin Todd owns the nearby K.A.R. Service repair shop. He didn't see the accident, but was onhand as the body and car were removed from the intersection."It looked very gruesome," he said. "The whole thing looked very sad."Todd says it is rare to hear of accident at this railroad crossing, in part because it is heavily patrolled by police."You see the police come by and make a big stink about people crossing the tracks, walking across when you are not in the cross walks," he explained. "It seems pretty well regulated."Livermore police say the crossing arms, the lights and sounds were functioning properly.