The Doomsday Scenario: a sinkhole

I honestly don’t know how far fetched the possibility of something like this happening really is, but if it did happen, it would surely qualify as the biggest man made disaster in the history of the world.
From Pam’s House Blend:

There has been speculation that the rapid outflow of oil from the underground reservoir is setting things up for a sinkhole. If that happens, it is almost certain that tens of millions of gallons of petroleum and tons of natural gas will be released all at once.
With this new evidence, the estimated amount of the spill has been upped to as much as 70,000 barrels a day. That is almost 3 million gallons every 24 hours.
There is, as yet, nothing to prove that the seeping oil is related to the drilling or the explosion. It is very likely that there is a causal relationship, however. At these depths (over a mile down, remember) sediment and rock behave differently than they do closer to the surface: rocks that are normally brittle are held together by the immense pressure. Disturbing that rock -- drilling, vibrations caused by drilling, an explosive release of gas, the sudden loss of pressure beneath the rock as oil and gas are removed -- can weaken its integrity and cause massive cracks. This is a well know scientific fact, one of the many that British Petroleum ignored in their greedy quest for profits.
In addition to oil coming out of the seabed, observers have noticed a rapid increase of already high amounts of methane (aka natural gas) in the outflow. From the Associated Press via Yahoo:
     It is an overlooked danger in the oil spill crisis: The crude gushing from the well contains vast amounts of natural gas that could pose a serious threat to the Gulf of Mexico's fragile ecosystem.
     The oil emanating from the seafloor contains about 40 percent methane, compared with about 5 percent found in typical oil deposits, said John Kessler, a Texas A&M University oceanographer who is studying the impact of methane from the spill.
     That means huge quantities of methane have entered the Gulf, scientists say, potentially suffocating marine life and creating "dead zones" where oxygen is so depleted that nothing lives.
     "This is the most vigorous methane eruption in modern human history," Kessler said.
Methane is extremely flammable in the presence of oxygen; it is believed that a sudden outgassing of methane is what caused the Deepwater Horizon rig to explode. As microbes "eat" methane for energy, they remove oxygen from the water, meaning that large quantities of dissolved methane usually results in vast anoxic regions where most life cannot exist. In other words, the outgassing is expanding "dead zones" and creating new ones. And, methane is an extremely potent greenhouse gas: when the gas begins to seep into the atmosphere, we will see a rapid increase in global warming and resultant climate change.
Even if the well were capped today and its outflow brought to zero, and even if the integrity of the rock is not further weakened and there is no sinkhole, oil and methane will continue to seep out through the sea bed for a very long time.

The blogger refers to what’s happening right now in the Gulf of Mexico as “ecological Armageddon.”
I cannot but agree with that assessment.