https://www.youtube.com/watch?v=PlL08CgBESc
Here is another witness on Youtube who was at Planet Hollywood and heard gunshots going off. She hid out with other people in a service tunnel/basement under Planet Hollywood.
Her brother saw Twitter posts that there were multiple shooters on the Strip when she called him to say what is going on.
Planet Hollywood sent a security team to lead the people out of the basement.
I watched yesterday. She is very credible.