Fire Breaks Perimeter of Los Alamos Lab

Firefighters battling a wildfire near New Mexico's Los Alamos National Laboratory deliberately set part of the lab's perimeter ablaze, officials said.

Firefighters said they believe a blackened ring of burned vegetation will protect the nuclear lab and the radioactive material it houses by denying the wildfire fuel, ABC News reported Thursday.

The fire, which has burned more than 90,000 acres, prompted a mass evacuation, leaving the city of Los Alamos a virtual ghost town.

The laboratory was to remain closed at least through Friday, lab officials said.

A plane equipped with radiation monitors flew over the lab Wednesday -- a move lab authorities said was a precaution.

Meanwhile, New Mexico Gov. Susana Martinez examined some of the first air-quality tests from the Los Alamos area. Although the sampled indicated a lot of smoke, officials said no radiation had been released.