Conditions and the record of those two buildings before the explosion. the national transportation safety board, which is in charge of pipeline incidents, says it will investigate once emergency crews finish searching for any more victims. federal investigators will focus on the gas pipeline itself and the utility company, con edison, and their operations. >> we'll be looking at con edison's integrity management system. we'll be looking at their call system to see how, to see how they handle complaints, phone calls reporting the to do have of gas -- to door of gas. >> reporter: con ed says it ...