Work On Friday

I am a janitor and one of my two places I clean is City Hall. So I was finishing on Friday and the police dropped by. They are able to come into City Hall after it is closed. Anyways I saw the cop car go by and I thought hope I didn't do anything. They came in and they said they got an alarm call. I told them it wasn't me. They asked me if I was the only one there and I said yes. Other then the people in the Emergency Communications Centre. So they got everything straightened out. I told them I tripped the alarm last time. So they left and nothing happened.