Lost Cat: Felix Missing in Indianapolis

My daughter’s kitty, Felix, seems to be missing. It has been a couple days since they saw him. My wife and I were at the hospital having our baby, and my mother in law was watching the house and kids. Felix goes outside with the kids and often hangs out, he always comes back inside with them and comes when called. He typically has a bell collar on but it had come off. He’s got a white face, with black/grey ears and is striped.