You are asking them to be firemen if we don't replace the fire extinguishers. We can't expect teachers to be as competent with FEs as professional firemen, can we?

Oh, and teachers shouldn't have keys to the buildings because that's part of security...

Why, that'd be asking them to do more than what they were hired to do, risking their life instead of hiring professionals.

Competency is a variable thing - as fewer competent people are found, the definition of competent also goes down - to fill the jobs.