HELP! engine making noise and coolant leak Options

[bouch-11]

okay so i have a 94 celica gts with the 5S-FE engine. i was driving today when all of a sudden it started making this sound. i got out and listened under the hood and it sounds like knocking in my valves almost. im not too sure what it is but there is a knocking sound for sure, like something is bouncing around inside. to add to this my engine coolant is leaking terribly. there is a steady stream of fluid coming out from under my engine. from where i can tell it is coming off of my drip pan so whatever is by that is leaking rad fluid. please help me i have no idea what it could be! a mechanic on the phone said it could be the water pump as it is attatched to the timing belt but im not too sure. anyone have any ideas?? thanks in advance for any help!