I was throwing a rooftop party and let my friend fly it. I had the prop guards on and she was learned pretty quickly. Therefore, I made the mistake of continuing to host the party. After a while, she flew close to a wall and suddenly, the drone flipped 90 degrees and and the propellers scraped the wall. This went for about 10 seconds until I shut it off. Two of the props turned black on the tips and got shaved off a bit (about 10% or about halt-1cm). I wanted to test if the drone would still fly and get some footage of the party so I flew for about another 1 or 2 minutes. After I landed, I touched the motors and I believe two of the motors were hot. I would say skin-scalding hot. I don't remember which one, but I'm assuming the ones that were not black (the ones that were probably stuck) were hot. I replaced 2 of the props (the ones that were shaved off) and flew the drone at my local park for about 15 minutes and everything seemed fine. I took it to about 500 feet, did some maneuvers. I'm wondering if I should replace 2 or 4 motors, or is the integrity of the motors still decent for another few flights. Any suggestion would be great! Thanks.