Explain the oil spill in the gulf for me?

from what ive been reading, bp was drilling in deep waters. they used some type of special sonar or whatever to find an underground well a mile deep in the water. they put in some piping to pull that oil up to a rig (which is like a big oil container). the rig exploded which i dont know why and sunk crashing into the pipe causing a gusher? now we cannot figure out a way to stop the gusher since it is so deep down. and we don't know how much oil is in this well under the deep water, do we? i heard there is 200,000 gallons a day coming out? so this is what im under the impression of what happened. however, im a pure mortal that doesn't know much about this whole story and wanted to get the details in laymens terms. please be specific so i can fully understand. thanks a bunch. no lame comments please.