OK This reminds me of an actual event here in the Cincinnati area. This was a few years ago and the person responsible is now sober and been off the alcohol for years but I still won't mention names.
This was in the days when fog was produced by mixing up 2 chemicals and then spraying the liquid in the air and the fog would be produced. It was heavier than air so it dropped to floor level quickly. Well this magician open his act by stepping out of an upright coffin into the fog. Well the stge manager starts to lay down the fog (the cuttains are closed) as he walks behind the coffin there is a hole in the back so he sprays some fog in there
and keeps walking around and laying out this THICK, TALL cloud of fog. The magi in the coffin starts coughing and hacking and tells the manager to "open the d**m curtain. Well the manager gave the word, the curtain opens, the magi steps out of the curtain and this HUGE cloud of THICK fog drops into the audience and completely covers the first six rows.
That was the last time that magi would work with thate stage manager for years until the manager joined AA.