Post-clark trading post fell to weather as of 2:45 p.m.
Saturday, the first time the building has fallen since October, said spokeswoman Stephanie Jones.
The building was built in the mid-1960s.
The roof is in good condition, she said.
The last time it was damaged was in November.
The city of Clark County has issued a demolition order for the building, which has been the focal point of Clark’s struggle to recover from a devastating wildfire that burned through Clark County, killing more than 50 people.
The county has been trying to rebuild from that devastating fire, which destroyed nearly half of the county’s roughly 1,800 structures.