Humans caused the February fire at a Muslim cemetery and a funeral home that was under construction in the northeast valley, but it is unknown whether the blaze was accidental or intentional, investigators said Monday.
The Clark County Fire Department and federal Bureau of Alcohol, Tobacco, Firearms and Explosives are investigating because of the site's religious connection and because of estimated damages between $1.5 million and $2 million.
The investigation has hit a barrier, authorities said.
"We have pursued a number of potential leads in this case, but none of them have allowed us to identify who caused the fire," Clark County Fire Chief Bertral Washington said in a statement. "Investigators have exhausted all available leads in the case, and we are seeking assistance from the public to provide further information about this incident."
Las Vegas police have helped with the investigation.
The blaze began about 1 a.m. Feb. 22 at 4425 E. Cartier Ave., near Lamb Boulevard and Carey Avenue.
Las Vegas does not have a mortuary that specifically serves Muslims.
The building was about halfway complete before the fire. It was a complete loss.
Officials said no information collected indicates the fire was a result of a hate crime.
Anyone with information about the incident is asked to call Crime Stoppers of Nevada at 385-5555.