A second bridge collapse in Tennessee killed one teen-ager and injured two others riding with him, officials said. Their pickup landed upside down on railroad tracks 25 feet below the 40-year-old wooden bridge near the eastern Tennessee town of Oliver Springs, Trooper Ray Fletcher said. It was not immediately clear whether a 25-foot section of the bridge had already collapsed or crumbled as the truck drove over it, police said. The collapse came two weeks after the failure of the Hatchie River bridge, 45 miles north of Memphis, killed eight people whose vehicles had plunged into the river. That accident was thought to have been caused by high water washing soil away from bridge supports. State Department of Transportation records show Hatchie River bridge deficiencies were discovered during inspections in 1985 and 1987.