I heard the sound of the air duct creaking

My co-workers and I were installing air duct in a commercial building downtown.

The commercial building was empty at the time.

Someone purchased the building and they were fixing it up. The people I was with and I were part of the construction crew. The air duct was 40 years aged and it needed to be updated. The owner of the commercial building also plans to update the entire Heating & A/C system after the air duct repairs were completed. My co-workers and I were toiling in the building all day on Thursday. The people I was with and I had songs playing on the radio and it was hard to hear. I thought I heard the creaking sound of air duct and I tried to warn our co-workers, but before I could get the words out of our mouth, the entire ceiling collapsed on top of myself and others and another guy. The pieces of metal and drywall covered the floor and there was dust everywhere. I should have gone to the emergency room after the accident. A piece of drywall fell right on top of our head and I had a pretty large bump. I had a headache most of the day, one of our co-workers thought I might have a concussion, although I continue to work the rest of the day, later that night I started to feel entirely sick. I was throwing up and entirely dizzy. At that time, I decided to go to the emergency room. It turns out that I really was suffering from a concussion. I got numerous afternoons off work and a paid mini vacation. It’s been almost a month since the accident and I still have a bit of a headache when I wake up in the day.
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