The number of manhole mishaps in the District this year already has eclipsed those in all of 2006, though the severity of the incidents — specifically, 300-pound manhole covers firing violently into the air — appears to be lessened by Pepco’s use of slotted lids.

Between Jan. 1 and June 30, Pepco reported 62 manhole episodes throughout D.C. — 36 smoking, 20 explosions and six fires — up from 58 in 2006.