A Sunday morning explosion at a middle school in southeastern Virginia injured sent five North Carolina workers to nearby trauma centers and three to emergency rooms. The workers were employees of T.R. Driscoll Inc. of Lumberton, North Carolina. They had been doing repair work at the school for approximately five weeks, when the explosion occurred. All five men were sustained injuries. The cause of the explosion has not yet been determined, but a police spokesman said the workers had been using propane to heat tar, which may have been a factor.