Tater Tot Casserole

1 pound ground beef
1 onion, chopped
2 celery stalks, chopped
1 can (16 ounces) green beans
1 package Tater Tots
1 can Cream of Celery soup
1 cup milk
1/2 teaspoon garlic powder

Brown beef with onion and celery. Mix soup, milk, and garlic powder in a casserole dish. Add green beans, beef mixture, and half of the Tater Tots. Mix together. Top with remaining Tater Tots. Bake at 350° for 1 hour and 15 minutes.