If your vehicle is in the flood in Lagos and you haven't started your engine yet, Don't start it..

Even if the vehicle is submerged and the water goes down, its likely water has made it's way into the engine (depending on the vehicle make).

The first thing to do is open your engine air filter compartment and bring out the air filter element to check for moisture, if it's moist or damp, do not crank the engine or attempt to start it at all.
Allow the water to go down, tow the vehicle away if possible. Get your mechanic to drain the engine oil and the transmission fluid. Do not take the risk of driving the vehicle at all.

Let the mechanic disconnect the fuel sending unit (fuel pump), pull out the spark plus one after the other and then crank the engine. You are making sure that water in each cylinder is blown out of the engine by the compression/exhaust stroke. Once completed for all the cylinders, connect the fuel pump (easiest way is to remove the relay or the fuse) and start the vehicle. It may idle rough, leave it and do not accelerate/rev the engine. Allow the vehicle to idle for thirty (30) minutes.

Once the vehicle is up to operating temperature, engage the gears after the other. From P to R wait 5s, R to N wait 5s, N to D wait 5s and N to R wait 5s and R to P. After this you can drive your vehicle.

Replace both the transmission fluid and engine oil after a week of driving depending on how milky they look.

Thank you.