Halar leggings

In TIFU fashion, this happened around 4 year ago.
A bit of background - Me and two others, at the time, had a kind of non-official placement at university, because we were all poor af but we had good skills, I was good at marketing, my friend was good at, well bassicly P.E, he wanted to teach and the other guy was just kind of there, he was added on last minute.
Ok, so my friend who wanted to be a P.E teacher, was invited to try out the equiment there, I got dragged along, cause I had nothing to do, and that other guy came too. So me and ths guy I barely knew were just watching my friend get sweaty by running around and stuff. Half way through, he fell over onto his knee. Now I'm a basic First Aider so I go to check him, I think hes fine, but the floor is all like carpety so the guy interviewing him told me to take my shoes, so I do , and cause I know my friend is fine but it's just a percaution, I put my shoes in the changing room. I come back out, and hes back up, then apparently the lesson is over so I go to get the shoes and he goes to get changed in the same room. As I putting my shoes on, my friend just randomly goes into the shower room, just one shower and a door. Then I just sit, and I don't hear the shower so I'm like wtf so I open the door, my friend bursts out, trying to make me jump, the door hits meI scream, loudly, slam the door back, just before that door hits my friend, I shout 'GET BACK!', he gets hit by the door, goes flying into the wall, then a ceiling tile literally fucking falls out of its slot, lands directly in front of my friend. Then silence. I'm fucking scared-shitless and with a concusion from the door, and it turns out he wasn't fine, his knee is actually fractured from falling over and the door hitting him , so, I pick him up, whilst I'm concussed and hes got a fractured knee, I've got his left arm and torse, carrying this guy, whos weighs lots more than me, I'm going dizzy, and I open the door with leg, then my back goes from the weight of him, I collapose on the floor, his body rolls onto the carpet thing, he gets bad carpet burns, and I fucking crawling across the floor, then I come to my senses, I suddenly realise that the P.E hall is empty, the lecturing room to the right has its emergency doors open to the outside, I'm freaking out thinking that something bad has happened, aside from me and him, then I hear like, a really loud siren, and then I just blackout.
I wake up, in an abulance, with two polices officers standing in the way of the back door, a paradamedic, looking at some paperwork and then IT clicks, what happened.
The university had recived some death threats or some shit like that recently, and were on edge. The guy who had just randomly put with us was a community police officer. When I shouted get back, apparently the P.E teacher guy heard that, then the roof tile fell, creating an all-mighty bang noise, he appparently runs into, I'm told afterwards, into the lecturing room next door, shouting about a gun shot, , the community support officer sets off the alarm, and gets everyone out and then we come out.
My friend's knee was put into a cast, I was almost jailed, but had to explain and show them the roof tile on the floor, the university was fined loads of money for a dodgy roof tile, and me and my friend were kicked out. I'm good friends with the community supprt officer now.
TL:DR - Knocked out a roof tile by mistake, people thought it was a gunshot and evacuted. Injury and halarity insue