A TANKER TRUCK carrying 30,000 pounds of mining explosives rolled over and spilled most of its cargo, forcing the closing of a 15-mile stretch of highway near Summersville, W.Va., officials said . . . A STRONG EARTHQUAKE shook the Adriatic coast of Yugoslavia Tuesday, causing a landslide that disrupted rail traffic, but no major damage or injuries were reported, Tanjug news agency said. The quake, measuring 5.5 on the Richter scale, rocked the northern Yugoslav coast in the republic of Croatia and parts of the central republic of Bosnia-Herzegovina at 5:42 a.m. local time.