It started in the bay of Bengal by two storms combining into one. It rushed through the bay and on the coast of Bangladesh.
The storm surge was that high, it was 7 metres, and it went over the embankments (barriers). The land was flat causing the water to move easier. If there were was an obstacle the wave wouldnt of been able to get to the village in Bangladesh.
When a cyclone is made the sun has to be 27C and it soaks up water. This is evaporation. Then there is condensation, but to of the clouds have to meet up then they combine a curved ne to make a thunderstorm. Then wind arrives on a curved path. It goes through the middle, creating high pressure. This is calm and dosn't bother but the eye wall has wind up to 100mph constantly. This makes a storm surge on the surface