This is good advice from a ServiceMaster website ...
"Flooded Basement: Safety First
Safety should always be the top priority. Walking on a wet basement floor can be extremely dangerous and even deadly. Before you walk onto a flooded basement floor, check for the following:
What’s the risk of electric shock? If you can safely get to the main breaker box, turn off the power before you go to the basement. If the breaker box is in the basement, call the power company or an electrician.
Is there a gas smell? Gas leaks are extremely dangerous. If you smell gas, immediately leave the building and call the utility company from a nearby home or business. Evacuate anyone else who may be in the building.
Is the water contaminated? Flood water can be contaminated with chemicals and biohazards like raw sewage, which pose serious health risks to people and animals. Stay away from contaminated water, and anything that’s been in contact with it. Make sure kids and animals keep their distance too.
Is the flooded basement still structurally sound? If there’s any doubt at all about the integrity of the basement or the house itself, stay out! Have the structure inspected before reentry."