Firefighters have almost completely snuffed out a fire that was threatening an underground physics lab.
The fire  broke out Thursday in the shaft to the Soudan Underground Mine State Park in northern Minnesota. The state's oldest, largest mine is home to the Soudan Underground Laboratory, host to a half-dozen physics experiments, including a 5400 metric ton detector to field neutrinos fired through the earth from Fermi National Accelerator Laboratory in Batavia, Illinois. On Sunday, firefighters with the Minnesota Interagency Fire Center reported that the fire appeared to be out after they poured thousands of gallons of water and foam down the shaft, according to a release  on the Fermilab Web site. Workers also descended down the shaft and restarted some of the pumps needed to keep ground water from entering the lab.
Firefighters won't declare the fire out until they've verified its origins, according to the release, but their quick work appears to have saved the $50 million lab, which has been hosting scientific experiments for 3 decades. "The immediate crisis has been resolved," says Marvin Marshak, a physicist at the University of Minnesota, Twin Cities, and director of the lab. He notes, however, that workers must still clean up the foam and make repairs to the shaft.