24 November 2004 Belleville Derailment Partly Human Error   Belleville-area residents were jolted by huge explosion.   The federal Transportation Safety Board (TSB) says several factors, including human error, contributed to a train derailment near Belleville, 21 Feb 2003.   Hundreds of homes were evacuated when two trains collided, one of them carrying liquid petroleum gas. The collision led to a massive explosion that sent several of the tanker cars into the air.   The safety board's report says it was a faulty bearing on one of the CP Rail cars that ultimately caused the collision just before dawn.   The TSB said the investigation also revealed that the derailment was more severe because the train had not slowed down to 5 mph or less, in spite of receiving a tone alarm from the hot box detector system.   Residents who live in the area, northeast of Belleville, say they were jolted out of bed by a huge explosion. It happened when an eastbound freight train derailed and collided with a stationary train.   Kim Nelles, the board's lead investigator in the case, says that, while a detection device did alert the driver that something was wrong, a better device would have given an earlier warning.   "There's Canadian rail operating rules that require them to take certain actions - to slow their train to what they call a slow speed, defined as 15 miles per hour," Nelles says. He says investigators recreated the accident, and determined the train could have avoided severe damage had it slowed down.   At the time of the collision, some nearby residents claimed the explosion caused structural damage to their homes.   Bob Guthrie is participating in a class-action lawsuit. He and his family still live near the railway, but they've since moved from their original home.   "There's still people in that area," Guthrie says. "We moved primarily because of the derailment. My wife had trouble sleeping. And we still haven't heard from the railway what they intend to do. This could happen at any time again."   But the safety board says a similar incident is unlikely. It says CP Rail has improved its technology that warns of a problem, so engineers now have more lead time to either slow the train down or stop it.