can or cannot

[eddkzk]

Which one should I use for the blank, 'can or cannot'? Thanks.
I think 'can' is correct, but I am not sure.
''People .................get into the chemistry laboratory under no circumtances''

[Soup]

Ex: People cannot get into the chemistry laboratory under no circumtances.

Below, negative no is first, so the verb can be affirmative can:

Ex: Under no circumstances can to people get into the chemistry laboratory.

[rj1948]

People cannot get into the chemistry laboratory under any circumstances.Correct?
Under no circumstances-means NEVER.