( CNN ) -- An explosion destroyed a home in suburban Pittsburgh on Wednesday , killing an elderly man and severely injuring his grandchild , authorities said . A house exploded Wednesday , killng one person and injuring a second , in the Pennsylvania borough of Plum . The explosion was reported about 1:30 p.m. on Mardi Gras Drive in Plum Borough , about 15 miles northeast of Pittsburgh . Several neighboring homes were damaged , fire officials said . Richard Leith , 64 , was babysitting his grandchild in the home , according to John J. Smith , an investigator with the Allegheny County medical examiner 's office . Both were transported to local hospitals , though Leith died later in the afternoon . The condition of the child , who was treated at Children 's Hospital , was unknown , Smith said . Leith 's autopsy would be conducted on Thursday , he added . It is unclear what caused the explosion . Dave Heiser , a neighbor , told CNN that he was home when he heard the explosion . `` I thought my house blew up . My windows were blown out . I went outside and debris was falling from the sky , '' he said . Watch the neighbor describe hearing the blast » . He said he ran three houses down and saw a woman running with a little girl and screaming . `` The little girl was apparently in the house when the explosion happened and was blown outside , '' Heiser said . `` That house was leveled to the ground . There is nothing left . '' Several families who were displaced by the explosion were directed to Red Cross officials to make arrangements for shelter Wednesday night , authorities said . E-mail to a friend . CNN 's Ninette Sosa contributed to this report .
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 .