The National Transportation Safety Board has released its preliminary report into last month’s nursing home explosion in Bristol Township, Bucks County, that left three people dead. According to the report, the facility’s maintenance director contacted PECO around 11 a.m. to report a natural gas odor in the basement boiler room and a first-floor hallway. An Exelon energy technician arrived at 11:50 a.m. and identified a leak on a meter set valve in the boiler room, according to the NTSB. The building exploded around 2:15 p.m.Exelon emergency responders arrived at about 2:42 p.m. and isolated natural gas flow to the facility about 3:50 p.m., the report shows. The NTSB said it was able to recover the indoor meter set and excavated portions of the service line that did not hold pressure during testing.