Am I Locked In or Out?

I had a make up quiz to take today during my lunch hour and as I entered the stairwell to make my way to the third floor, I heard the door lock behind me. Suddenly, I was scared. I had forgotten about the locking of the stairwells during class time. When I grabbed the handle on the third floor door, it didn't move. "Oh, no. It's locked!" I was locked between two floors; in a school which has violently been torched twice. I started to bang on the third floor door frantically; then the second floor door. Back and forth I went until someone heard me and opened the door from the other side. I am thankful for the people skipping class and wondering the halls; without them I would have been stuck in the stairwell for 50 min. If locking the stairwells is for our protection, imagine being locked between floors with the wrong person. Very scary...but that's High School.