Attorneys for the victims' families retained the experts and this was the first time a group of lawyers and experts have been allowed to tour the site.
Lawyers Bob Reardon and Reese Norris spent three and a half hours at the site, guided by OSHA and said they could walk anywhere they wanted except for areas that are still unsafe.
Their visit was inconclusive, they need to see the evidence police have stored, and they'll want to return, Reardon said.
"The devastation was massive throughout," he said.
Henry Lee said he would need more information to reach a conclusion. He's taken the case pro bono but the lawyers have made a donation to the University of New Haven, where the Henry Lee Forensics Institute is to open in October.
Bob Reardon said the tour is the first step in the lawyers’ investigation into what caused last month's explosion and they would most likely need more visits to the site before they reach any conclusions.
The attorneys will appear in court on Monday to ask a judge permission to view evidence collected after the explosion, which is being held in a nearby warehouse.
Lee took the tour with Dr. Dehon Kong, an expert on gas explosions, and Thomas Klem, is an expert on fire origin.