I'll take it you have an In-Ground pool John and if so, sounds like water is erodind the soil under your walk and making it start to seem like a sink-hole. I wish it were't so but sounds like some digging and excavating is in order. Tim Hewitt in Va Beach should be able to help...he's a contractor and member here on HomeTalk and here's his profile page...Best of luck! JL (you'll have to do some digging to see where the water is coming from!) Tim's profile page is: http://www.hometalk.com/member/jrtcwjn4c6

There are folks who will come out and perform "mudjacking" services. They drill into the deck and fill the voids with a material they pump in from a truck. This may lift the slab back into place, but it does not fix the underlying issue. I'm with JL. Unless you fix the issue, its throwing good money after bad,