An unexpectedly powerful Trinity test

What if one of the first atomic explosions unexpectedly produced a megaton-scale yield?

The accidental-fusion premise is rejected; under the hypothetical larger yield, severe danger to the Trinity observers and disruption of the project are expected.

The premise that an early atomic weapon accidentally turns into a fusion weapon is rejected before the imagined consequences are explored. An unexpectedly megaton-scale Trinity test would exceed the observers' planning assumptions. There is initial disagreement over whether a bunker might protect them, followed by a much darker estimate of casualties among the project team. The later exchange separates uncertainty about explosive yield from uncertainty about the effects of that yield. These are speculative consequences, with no reliable survival calculation established.