BUFFALO, N.Y. — ATF investigators are already facing a challenge, as they begin their investigation into what caused a 4-alarm fire on Main Street.
"We have heavy machinery on scene but unfortunately we aren't going to be able to use those pieces of machinery today due to the stability of the building," ATF branch chief Walter Shaw said.
Shaw says the building's structure is sitting on top of a full basement but it can't support the weight of the equipment they need. So instead, they're having to collect any evidence the old-fashioned way: by hand.
There are many local and state agencies helping to stabilize the building, including a fire department unit from New York City.
"Hopefully towards the end of this week or the end of next week, we come up with a hypothesis that we like, that can explain how this fire started and what actually happened to the fireman," Shaw said.
The same day of the fire, Buffalo Fire commissioner William Renaldo said workers had been doing some work to the building with a blowtorch.
City officials say they did not have a permit.
"Investigation is continuing. As far as the matter of the lack of permits, there's going to be more to follow on that. That's all I can say as this point," Renaldo said.
ATF has interviewed those workers.
They continue to interview witnesses and collect video from nearby businesses.
As for Arno's death, Renaldo says a second backdraft could be to blame.
"We do believe there was a second backdraft as well. We believe the first backdraft caused part of the structural collapse. Jason was covered by a significant amount of debris and that's why they were not able to retrieve him in time," Renaldo said.
Details about Arno's funeral and wake can be found here.