Why did Walt destroy the Meth Lab?

Earlier on in the episode it was detailed that the DEA were already on to the Laundry place (the scene with Hank discussing why a laundry place would need two 1700 amp power panels, and how a laundry of that size would need less than half of that).

While destroying the lab focused the attention of the DEA, they were already hot on the trail anyway. Furthermore, Gus had just been killed, which would have bought additional heat down on the laundry place. Leaving it in tact would have left more evidence behind than what they actually found and clearly demonstrated the scale of the current operation. I'm not sure that blowing it up would have left much evidence tying Jesse and Walter to the scene though, since the vast majority of their work in the lab was done in protective clothing with gloves on.