Officials : 1:30 p.m. It 's unclear what caused the blast , authorities say . Investigator : 64-year-old Richard Leith died at hospital . Neighbor says he saw a woman running down street with a little girl after blast .
Officials : 1:30 p.m. explosion kills grandfather , severely injures grandchild . It 's unclear what caused the blast , authorities say . Investigator : 64-year-old Richard Leith died at hospital . Neighbor says he saw a woman running down street with a little girl after blast .