Considering that they ran the thing with no cooling system or containment, the burial doesn't seem so bad.
From the
wiki:
"
On December 2, 1942, CP-1 was ready for a demonstration. Before a group of dignitaries, a young scientist named George Weil worked the final control rod while Fermi carefully monitored the neutron activity. The pile reached the critical mass for self-sustaining reaction at 3:25 p.m. Fermi shut it down 28 minutes later."
"
After the first self-sustained nuclear chain reaction was achieved, a coded phone call was made by one of the physicists, Arthur Compton, to James Conant, chairman of the National Defense Research Committee. The conversation was in impromptu code:"
"
Compton: The Italian navigator has landed in the New World.
Conant: How were the natives?
Compton: Everyone landed safe and happy."
I guess the operator ran up the ladder & worked the control rods manually. Basically, they got lucky.
