Pets

This should be bookmarked by every indoor cat owner.
I'll add three things to the list from my personal experience losing Petunia for two full days.
One, look under sheds and holes that you think are too small for your cat to fit into. Remember, the hole needs only to be big enough to hold the hight and width of her head and whiskers.
Two, if you have a second cat that happens to be indoor/outdoor, he it she will find the indoor cat. Follow them with plenty of space for them to do their thing That worked finding Petunia, and finding Mufasa, the very first time we let him out once he was old enough. He ran like he was escaping and hid maybe half a block away in a wooded area and Nugget found him. We encouraged Nuggets search every step of the way and he searched for Mufasa almost with the same intensity a mother would. What a relief that was as Moofy is to this day, my all time favorite cat. (Please don't tell Petunia) As smart and absolutely invested he is in learning what Tracy does, (remember, I brought him with me when I left her house two years ago and he kept going back to her house like a magnet)and when I'm there, he remembers me as his first rescuer and he is as lovingly grateful today as he was the first day, if not more so.
Also, and I know I'm preaching to the choir, but talk to your cat, sing to your cat, please let him/her know your voice as comfortably as he would their most familiar blanket or sleeping spot.
Sorry for the length, but three, if it's safe, leave a patio door open, and they may well return in the middle of the night.
I pray this never happens to you, I did not sleep for two days straight
Train the kids or other regular visitors as to your cat's status, and if they can't respect it, please consider placing stricter visiting rules so they won't be unsupervised at your house.(Visitors lol)