My bird nest bottom fell out and there was five babies in there and they all perished and I put the bottom up somehow the screws come off and now that I put the old nest back in there and now the mama bird just comes to that nest when there's nothing t

Im afraid that’s  nature. Raptors//Birds of Prey take young birds and other wildlife as well .l every day That is nature! I’m afraid you will have to except!

Understandable that you intervened, but as is always the case, nest boxes should be left alone until the end of the breeding season. Even then, putting nests back into boxes isn't good practice.