Our Poor Kitty Trootie

This morning we discovered our backdoor was wide open. When that happened we can't be sure. We do know that my son was the last to close the door. We have three cats. Tom is a beautiful huge gray kitty and the sweetest cat I have ever had. Riviera is a siamese. She can be nice but generally only when she is hungry or decides she wants your lap. Those lap moments are rare but we love to get them none the less. Then we had Trootie. She was a very petite kitty. She was white with splotches of calico in her. We rescued her when she was a couple of months old. We named her Trootie because my husband works for IHOP. One of there main dishes there is the Rootie Tootie Fresh and Fruity. Hence Trootie's name. She was sweet but very skittish. She had a routine every night. When we were getting the covers ready for bed, she would jump up and decide it was time to play. She also loved night time because she could cuddle up against our legs or make a spot on your chest as her bed.
The miracle I suppose if there is one, is that when the door was left open, my other two kitties decided to stay in the house. Our dear Trootie who is almost a year old, decided that she would go out. We can't find her at all. I have searched mulitple times through the day, in every place I can think to look for her. I don't think it helps that behind the fence in our backyard is all woods. After both of the kids came home from school, I had to tell them what happened. Both broke down in tears. My son feels guilty. I explained to him that there is nothing he can do about it now. Mistakes happen and God willing, Trootie will come back to us.
After the kids went to bed tonite, I went out with my flashlight and searched again. No luck. Not even a stray meow. We have set food and water out in the front yard and back yard. I can only hope that she will return to us.