MLB Out or Home Run: When Does a Fallen Catch Count?

Question
In major league baseball, if an outfielder catches a fair fly ball and falls over the outfield fence, is that considered an out or because his momentum carried him over the wall, woud that be a home run?

Answer
Hey John,

If his feet are IN fair territory, then it would be considered a "CATCH."
If he completely jumped in the stands and caught the ball, then it is a home run.  Think of it in terms of someone trying to catch a foul ball, so he opens the gate and waits till it comes down to him... NO CATCH!

Dennis