Las Vegas, NV (KTNV) -- Investigators said it appears homeless people are responsible for a fire at a vacant building Monday morning.
A Las Vegas police officer spotted the flames in the building near 9th Street and Stewart Avenue.
Firefighters arrived quickly and were able to confine the fire to one room.
Las Vegas police said it is the second fire at the old apartment building in the past few days. The first fire was on Thanksgiving Day.
Residents of a nearby apartment complex say they are on high alert after the fires.
Fire investigators said the first started in mattresses inside of rooms in the vacant building.
Adam Vance, who lives in the building next door, said he has seen as many as 20 to 30 homeless men use the building to sleep in, even after the first fire. He thinks it will only be a matter of time before the building catches fire again.