I read the book a long time ago and various google searches have not been helpful, there are two stories that have really stuck with me and they may be from two seperate books. The first was a short story called just deserts(sp) where a kid was flying in a plane with his parents and it crashed because he didn't put the fuel cap back on. He was the only survivor and no matter which direction he walked he always came back to the crash site. The second story was about kids in a swimming hole and something in the water was drowning them. It ended with this kid on the phone with his friend and the thing from the swimming hole came out of the pipes or something, any help would be appreciated.
You can look up the titles of stories on the Internet Speculative Fiction Database. If you remember the title of the story correctly, it's “Just Deserts” by R. C. Welch, published in his 1995 collection Scary Stories for Stormy Nights. According to the blurb, the swimming hole story is also in that collection.