Minnesota Department of Natural Resources ice safety tips

Cold facts about ice

-- No matter what the temperature outside, ice seldom freezes uniformly. It may be a foot thick in one location and only an inch or two just a few feet away. That was the case Saturday on the St. Louis River.

-- Ice formed over flowing water and currents is often dangerous. This is especially true near streams, bridges and culverts. Also, the ice on outside river bends is usually weaker due to the undermining effects of the faster current. The lower St. Louis River is especially hazardous because changes in water-flow rates affect currents that can change ice thickness rapidly.

-- Ice thickness can change rapidly from week to week. The ice where Adam LaPorte's vehicle went through was thick enough just a week ago to support his truck.

-- New ice is usually stronger than old ice. Four inches of clear, newly formed ice may support one person on foot, while a foot or more of old, partially thawed ice may not.

Driving on ice

-- Stay off the ice at night, especially during a snowfall. If that's unavoidable, be very cautious and drive slowly since holes can open up very quickly. If you drive too fast you might not be able to stop in time.

-- Don't wear a life vest while riding inside a car or truck. The extra bulk could hamper your escape through a window.

-- If your vehicle breaks through the ice, the best chance of escape is immediately. Get out of the vehicle as soon as possible. Vehicles will stay afloat anywhere from several seconds to a few minutes.

-- Ice safety experts recommend that you have your seatbelt unfastened at all times on the ice.

-- Some people travel on ice with windows open or a door ajar. Electric windows may fail and doors may not be able to open due to water pressure or ice obstructing them. Try kicking out the windshield or rear window.

-- Tests show that many vehicles with the motor in the front will fall front end down first, often flipping over onto the roof if the water is 15 feet or deeper. This can cause people still trapped inside to become disoriented on what is up or down. Remember, visibility is likely to be nil.

-- Don't go back into a partially submerged vehicle to retrieve equipment.

More ice tips

-- Check with a local resort or bait shop about any known danger spots such as aeration systems or traditionally unsafe areas before heading out on the ice.

-- Have a plan of what to do if you do break through. Carry rope, ice picks and a flotation device to help save your life or that of a companion.

-- Don't be the first to drive in an area.

If you fall through ice while walking or escape from your vehicle:

-- Don't remove your winter clothing. Heavy clothes won't drag you down, but instead can trap air to provide warmth and flotation. This is especially true with a snowmobile suit.

-- Turn toward the direction you came. That's probably the strongest ice.

-- Place your hands and arms on the unbroken surface. This is where a pair of nails, sharpened screwdrivers or ice picks come in handy in providing the extra traction you need to pull yourself up onto the ice.

-- Kick your feet and dig in your ice picks to work your way back onto the solid ice. If your clothes have trapped a lot of water, you may have to lift yourself partially out of the water on your elbows to let the water drain before starting forward.

-- Lie flat on the ice once you are out and roll away from the hole to keep your weight spread out. This may help prevent you from breaking through again.

-- Get to a warm, dry, sheltered area and warm yourself immediately. In moderate to severe cases of cold-water hypothermia, you must seek medical attention. Cold blood trapped in your extremities can come rushing back to your heart after you begin to warm. The shock of the chilled blood may cause ventricular fibrillation leading to a heart attack and death.

General ice thickness guidelines for new, clear ice only

2 inches or less -- Stay off

4 inches -- Ice fishing or other activities on foot

5 inches -- Snowmobile or ATV

8-12 inches -- Car or small pickup

12-15 inches -- Medium-sized truck