The worst 30 minutes of my life

Literally, I don't think I have ever been more afraid, sad, mad, and terrified in a span of 30 minutes as I was last night. Craig went outside to tell Jonas and Carleigh it was time to come inside, only to discover that he couldn't find Carleigh, and none of the other kids knew where she was either. I half-calmly walked around the center of our apartment complex, calling her name and checking the pools and playground. All the kids who know Carleigh were helping too- about 15 of them. After I made the full circle and Craig had too, I was no longer calm and began to imagine the worst. After 20 minutes I called 911. I was mortified- the idea that I was on the phone with the police because my adorable blonde blue eyed daughter was lost...even writing that makes my stomache drop. They said an officer was on the way and to take my cell phone and keep looking. At one point, either going up some stairs on when I finally found her, my forehead touched the ground because I have a scrape there today. I remember praying for calmness, but I also think I literally hit my knees in relief when she calmly walked out of a friend's apartment.
Turns out she had seen a friend and ran to her apartment and started watching a movie with her. I know this girl vaguely, but didn't know what apartment she lived in. They hadn't heard us calling for Carleigh because the tv was up and the doors and windows were closed. Her mom had happened to open the door to put something outside when Craig rode by on his bike yelling for Carleigh. She said "She's in here," and out walked the angel herself. It was about this time I rounded the corner and the police car drove through the gate. The officer was nothing but compassionate and nice. She made sure I was who I said I was and left. Carleigh didn't understand why she couldn't stay and finish the movie, but I had to get home and breathe.
I was much more upset with myself than with Carleigh. She's 4~ what am I thinking letting her play outside with only 8 and 10 year olds to look out for her? That's not their job! It's mine, and I failed. Thank God she is okay and she and Jonas both understand now why I've always said not to go in anyone's house without me knowing about it (Jonas was visibly shaken by all of this, too). I don't plan to permanently attach her to my hip from now on, but I do plan to be much more careful.