CAMP RIPLEY – The scenario was this: Somewhere in remote Minnesota, an oil train had derailed, and the ensuing fire raged beyond the reach of traditional firetrucks.

The fix? A thundering CH-47 Chinook helicopter rising from an airfield, its twin rotors beating the air with nearly 10,000 horsepower as it lifted a Canadian Pacific firefighting rig fitted with water bladders and firefighting foam.

The train derailment was fake, but the response Tuesday afternoon was a real test of the National Guard's ability to help fight a rail fire. If this were an emergency, the chopper could carry the rig to a fire anywhere along the rail line.

"We want to prepare for the worst-case scenarios in our state," said Col. Scott St. Sauver, garrison commander for Camp Ripley. "As citizens, we expect our National Guard to take care of us on a bad day."

The Chinook demonstration was one of several Tuesday afternoon at Camp Ripley as the National Guard engaged in annual "Vigilant Guard" training exercises meant to test the Guard's ability to help during extreme emergencies.

Minutes before the Chinook spun up to liftoff, Guard members elsewhere at Ripley responded to a fake natural disaster and chemical spill that left civilians wounded, buildings toppled and a city threatened by a toxic cloud that required the Guard's decontamination unit to suit up and head into danger.

The training exercises were two years in planning, said St. Sauver. Some 1,100 Minnesota National Guardsmen, 320 other military members from across the country and nearly 500 civilians will take part in the weeklong training in Duluth, Camp Ripley and the Twin Cities.

The exercises were also a test of the Guard's ability to work with civilian agencies, like city fire departments, emergency medical technicians and police officers. Some of those agencies, including the Minneapolis Fire Department, sent people to Camp Ripley this week for the training exercise.

One of the day's biggest tests involved a script that was like something out of a B-grade horror movie, with multiple disasters designed to test various functions of the National Guard's training. First, a storm carrying straight-line winds knocked down buildings and injured people. Then two trains freighted with liquid chemicals collided. Finally, a sinkhole opened underneath a university, swallowing the medical and chemical departments.

An initial search of the sinkhole by one of the Guard's Civil Support Teams revealed the presence of a nerve agent, requiring a response from the Guard's CERFP team, or Chemical, Biological, Radiological, Nuclear Enhanced Response Force Package.

In everyday Guard duty, the state's Civil Support Team is on standby 24 hours a day, ready to identify chemical, biological, radiological and nuclear threats. The team includes an analytical chemist who can operate out of a mobile truck equipped with highly specialized gear to not only test samples from a disaster site, but also predict where the chemicals might spread and who should be evacuated.

During Tuesday's drills, the soldiers suited up in white, one-piece coverings and orange rubber boots before heading into the spill zone, then practiced decontaminating themselves after they returned to a safe area.

"In a real-world situation, we need to know what we're doing so we don't harm ourselves and we can help civilians," said Sgt. David Williams of the Wisconsin National Guard.

Nearby, wounded civilians, played by volunteers, moaned for help. One by one they were lifted onto stretchers and carried into a field hospital.

Liz Imberi from Brainerd said she was shopping at Wal-Mart recently when someone stopped her outside the door and asked if she wanted to help the Guard with their training. She accepted, and on Tuesday she played the part of a person who had run from a storm only to fall and injure herself. Her face smudged with dirt, she waited for medical attention as Guard soldiers did triage.

"I think I'll be OK," she said, smiling.

Matt McKinney • 612-217-1747