YOUNGSTOWN, Ohio — After spending their first full day on the ground in Youngstown, officials from the National Transportation Safety Board (NTSB) provided more details into the investigation into Tuesday's deadly blast inside a downtown building during a Friday night news conference.
Specifically, the agency laid out a timetable of events that took place inside the Realty Tower building prior to the explosion. Investigators have been focusing on an abandoned gas line in the basement of the building that had been cut, yet was found to still be pressurized with gas.
NTSB officials spent time Friday interviewing workers who had been in the basement prior to the explosion. The focus of the work being done was apparently "to clear out old piping and other outdated infrastructure and debris from the basement and the vault area, which extends under the sidewalk adjacent to the building." That work was done ahead of a planned city project to replace the sidewalk.
According to NTSB board member Tom Chapman, the four-person crew was "unaware that one of the pipes in the vault was pressurized at the time, nor did the work crew have reason to believe that there was gas present in the pipe."
Chapman added that "no gas was smelled during the day as the crew was working in the basement," which he said indicates that there was no ongoing leak throughout the day on Tuesday.
The crew in the basement made two "initial cuts" into piping along the basement wall. Chapman stated that when a third cut was made, the crew realized that gas had been released.
"The work crew evacuated the basement, alerted the bank employees upstairs, and pulled the fire alarm," Chapman added. "The workers were instrumental in alerting residents in the upstairs apartments and they assisted in helping to evacuate residents."
According to Chapman, the explosion happened approximately six minutes after the pipe was cut.
Newly-released surveillance video from inside the building shows moments just prior to the blast, as residents hastily evacuated the scene amid the fire alarm.
While the NTSB has been able to conduct interviews and review video, their team has not been able to enter the building itself.
"There are very serious concerns about the integrity and safety of the structure," Chapman noted. "Consequently, access is not currently possible by us -- nor by anyone -- until appropriate determinations are made regarding its safety."
Those determinations will be made by city, county, and state officials, according to Chapman.
You can watch Friday night's NTSB briefing in the player below.
Chapman reiterated that investigators do not believe there was anything suspicious about the cut line. "All indications are that it was very much an accident."
NTSB investigators will be in Youngstown for approximately one week. A preliminary report from the agency will come in approximately 30 days, with a final report to be released in 12 to 24 months.
The NTSB says it is leading the investigation because pipelines are considered a mode of transportation.
One person was killed and seven people hospitalized as a result of the explosion that took place at around 2:45 p.m. on Tuesday. The blast shook the downtown Youngstown area as bricks, glass and other debris littered the sidewalk. The body of 27-year-old Chase Bank employee Akil Drake was recovered in the early morning hours of Wednesday.
Previous Reporting:
- WATCH | Video shows people escaping Youngstown building before deadly explosion
- National Transportation Safety Board says cut gas line will be 'central focus' of Youngstown building explosion investigation
- 'This tragedy hit our community pretty hard': Youngstown officials provide update following deadly explosion at Chase Bank building
- Boyfriend of Chase Bank employee critically injured in Youngstown explosion says she faces a long recovery
- Updates: 1 found dead after explosion at Chase Bank building in Youngstown