Are you playing a game? Not even a sophomoric question; were back in grade school, are we?
It's the same principle for which firemen use extreme caution when gaining entrance to a burning building. Fire and heat create gases which expand and pressurize the air. Once the containment is breached, poof, or in some cases, a mighty whoosh of air as it seeks equilibrium with outside pressure.
Now here is question for you. Failure to answer will reveal you have no clue.
Given they were explosive squibs, how did they mask the noise and the flashes as demonstrated in this video? Buddy
Undo what Wilson did