Was out on the lake this afternoon and everything was running fine. After sitting for about 30 minutes, I started it up to head back in. I noticed the steering was tough but didn't think that much about it. About 10 seconds later, the alarm went off. I looked down and saw the temp at about 225. I immediately shut it down. <br /><br />Turns out, the serpentine belt fell off. I have no idea how it did that. It isn't broken at all. I was able to wedge it back on all of the pulleys. I tried to to start it up and it sounds like the engine is locked. The starter goes, but it immediately stops. The engine simply won't turn over. <br /><br />Any ideas what could have happened? I didn't think there would be any damage because I shut it down so quickly, but something is obviously wrong. <br /><br />Thanks in advance. <br /><br />5.7 Mercruiser EFI