The two possible scenarios are either a complete collapse of the ocean floor right above the Deepwater Horizon well and surroundings or a partial collapse in the form of a mud slide on one side of the well.
The first scenario is unlikely at this time but remains a possibility given the number of crevices that have been created naturally due to the high pressure inside the well. This pressure is created by the large amount of methane gasses that is building up inside the well.
Should this scenario occur, then the prediction is that a vast amount of oil and methane will be released immediately into the water and towards the surface. The aftermath would be a tidal wave, caused by the fast displacement of a large amount of water that will reach the shores of all the Gulf States.
The immediate danger will be to cope with the height of the wave along the shoreline and not necessarily the mixture of oil and Corexit. Both products will obviously affect the local population in the aftermath of the tidal wave and during clean up.
The second scenario, a partial collapse of one side of the well in the form of a large mud slide, will cause a similar effect but to a far lesser extent given that the collapse will happen in a more or less slow motion fashion where water will replace oil and methane over a brief period of time.
A wave is expected to form off the Gulf Coast but will cause less damage and will be far less destructive.
Nevertheless, the impact on the states of Louisiana, Mississippi, Alabama and Florida will be enormous. The tourism industry represents a combined annual income of 150 billion dollars for Alabama and Florida. This industry has been hit hard and may not be able to recover within the next few years after a collapse.
The fishing and shrimping industry that represents the livelihood of small business owners will be affected for at least 10 years and maybe longer.
The ports of New Orleans, Pascagoula and Mobile are and will be inaccessible until the cleanup has been completed. The three ports rely on European and Asian trade for 50% of their annual revenue.
The environmental impact is hard to measure but one thing is certain; 80% of the world's dolphin population lives in the affected area of the Gulf of Mexico and the whale population migrates to the region to have their babies there.
The BP solution to place relief wells to pump out the oil and methane gas may seem like a good solution but it also represents serious dangers to the integrity of the well's surface and may cause further cracks and crevices to open.
For the time being this may be the only solution available and let's hope that the first scenario never occurs.