Sweeping communications outages continue to plague large parts of Tennessee as US federal investigators combed the site for clues after a camper van exploded in Nashville on Christmas morning.
Police emergency systems in Tennessee, Kentucky and Alabama, as well as Nashville’s Covid-19 community hotline and a handful of hospital systems, remained out of service due to an AT&T central office being affected by the blast.
The building contained a telephone exchange, with network equipment inside – although the company has declined to say exactly how many people have been affected.
Investigators have revealed that a person of interest has been identified in the wake of the explosion, and that person’s home is being searched.
The heart of Nashville’s tourist scene – an area packed with bars, restaurants and shops – was shut down as experts examined debris and the damaged buildings to learn more about the explosion.
Authorities say they are certain that the blast was a deliberate act.
Mayor John Cooper has enforced a curfew in the central area until Sunday via an executive order.
AT&T said restoration efforts are facing several challenges, which include a fire that “reignited overnight and led to the evacuation of the building”.
This has forced their teams to work with safety and structural engineers and drilling access holes into the building in order to reconnect power.
“Our teams continue to work around the clock on recovery efforts from yesterday morning’s explosion in Nashville,” the company said.
“We have two portable cell sites operating in downtown Nashville with numerous additional portable sites being deployed in the Nashville area and in the region.”
State governor Bill Lee asked the White House for federal assistance due to the “severity and magnitude” of the explosion’s impact.
At least 41 buildings were damaged, and communications systems – including residential and mobile phone services and emergency call centres – failed across the state, he said.
Kentucky and northern Alabama were also affected.
Ray Neville, president of technology at T-Mobile, said on Twitter that service disruptions affected Louisville, Nashville, Knoxville, Birmingham and Atlanta.
The outages had even briefly grounded flights at the Nashville International Airport, but services have continued normally as of Saturday.
According to Metro Nashville police chief John Drake, police officers were responding to a report of shots fired when they encountered the camper van blaring out a recorded warning that a bomb would detonate in 15 minutes.
Police evacuated nearby buildings and called in the bomb squad. The vehicle exploded shortly afterwards.
Law enforcement officials have said they believe the blast was intentional but have not yet established a motive or target.
Mr Lee tweeted: “This morning I toured the site of the bombing. The damage is shocking and it is a miracle that no residents were killed. (First lady Maria) and I continue to pray for those who sustained injuries from the blast.”
The governor had been in quarantine due to his wife contracting Covid-19. However, the Republican said that he and Maria have both tested negative, allowing the two to visit Nashville.
On Friday, Mr Drake told reporters that investigators at the scene “have found tissue that we believe could be remains, but we’ll have that examined and let you know at that time”.
Three people taken to hospital for treatment are in stable condition.
The FBI has taken the lead in the investigation, agency spokesman Joel Siskovic said.
Federal investigators from the Bureau of Alcohol, Tobacco, Firearms and Explosives are also involved in the investigation.
The FBI is the primary law enforcement agency responsible for investigating federal crimes, such as explosives violations and acts of terrorism.