Goby Disappearence!

Hello everyone!

I woke up this morning to find my goby gone! It is an orange spot goby, and it never moved far away from his home. It lived with a pistol shrimp, and they were super happy. I don't have any fish in there that are aggresive or are not compatible with gobies. I have a cleaner shrimp in there, but that's it. Please help, I am super worried. I also think the pistol shrimp is gone, maybe they dug away together under the sand?

Thanks for the help!