Someone called police to Broadhurst's home to check on his welfare about the same time the fire broke out, but Anderton had no details as to who made the call or why they thought Broadhurst may have needed help.
Investigators have not been able to identify the accelerant that was in the house or where the fire originated.
"I don't know that we'll ever truly know the exact cause of the fire," Anderton said. "We'll just know it was an act of intention."
The fire was reported just after 7:20 a.m. Friday and leveled the two-story home, leaving just the frame and foundation. Neighbors ran to help Broadhurst, who was flown to a hospital.
Unified Fire officials said Monday in a news release that while the exact cause of the fire has not yet been determined, investigators with the assistance of Questar Gas have ruled out natural gas as playing a role.
"At this time, it is believe[d] that some other form of accelerant, as detected by trained canines, was used and contributed to the rapid fire spread," the news release reads. "UFA is not currently pursuing any active leads or suspects."
The rest of Broadhurst's family was away from the house at the time of the explosion.