The hole for the two 1,000 gallon propane tanks had to be blasted. By putting the tanks underground, they can be filled to 90% of capacity instead of 85%, and at 2,000 gallons that’s 100 gallons of difference.
The blasters drilled this shot in a wide chevron pattern, with the points of the chevrons facing west. The blast went from east to west in sequence to minimize the amount of material thrown out.
Sometime things don’t go exactly right! In this case, there was a large vein of softer pink rock which focused the shock wave toward the west side, causing a bit of rock to be thrown high into the air. Bill was shooting this movie, looking east, and it turned out we were a little too close, so a a few bits had to be dodged. This was easy, since only a few went as far as where we were and those were thrown almost vertically, so we had lots of time to figure out where each one was going to hit!
Here’s the shot seen looking to the south, which make it easier to see the trajectories of the bits that got thrown around.