chill and snow numbed workers' hands.]]> gravity.]]> increasingly rare.]]> officials say.]]> point in the ride where passengers experience zero-gravity, making them feel weightless for a moment.]]> track where the wheels go.]]> designer.]]> construction crew of about 35 men is from Idaho.]]> disturb people who live near Great America.]]> business, owner Fred Grubb built coasters at Silverwood Theme Park in Idaho.]]>