Gentlemen,
Thank you so much for taking the time to respond---I feel like I have just been indoctrinated into hydraulic lock 101. So very informative---thanks again. I definitely will feel more educated when I talk to my mechanic tomorrow, and sooner than later my waranty co. and BMWNA, as necessary.

I live 10.08 miles away from work, and do that drive every other day, for only 2 days a week (firefighter schedule, 1 day on - 24 hrs., one day off - 24 hrs, 1 day on, 5 days off), and then I travel many miles more than that during the course of the week. To put it mildly, I bought the car with 30k miles on it 3 yrs. ago, and have put 60k on it to date. So, I am wondering if the condensation theory really applies to me, put I am going with it because I think all of the stars have aligned for before in a bad way....
SCENARIO the day it happened:
I worked the overnight, the temp. outside was about 15 degrees, the car sat for 24 hours in thie cold (usually is housed in a garage), I started it up, seemed like a rougher start than normal, and went back into the firehouse for about 1/2 hour. When I came back out, the engine was off (siezed at this point, I'm assuming), I tried to start it again, no luck, tried to jump it, no luck....had it towed to my mechanic, and Presto, I have "hydrolocked my engine". My mechanic knows a guy that worked at a local BMW dealer for years, so my car is actually with him, in his home garage getting repaired. According to this new mechanic, he is very familiar with this problem, as he has seen it before, and thinks he can fix it without further problem...the issue is the REASON for the cause of the hydraulic lock, which I think you guys have been so generous in helping me understand. So that's it in a nutshell...
Oh yes, I see that Frank asked about the extent of the repair...the mechanic mentioned that the plugs were crushed...I know that may make sense to you, but I assume that the rods (don't know how many) are completely shot, and the plugs took on a force that was obviously huge...the repair bill is not set in stone, but is in the upwards of 7k+....but the warranty cost me 4k...all of which I will loose if I'm not careful on how I present this case to the appropriate "suits". That's a total of OVER $11,000 for a problem that I couldn't anticipate OR PREVENT due to a bad seal design....hmmmm. I'm frustrated, and that's putting it mildly.

So, THANKS GUYS for ALL of your time to help me!!! I will respond back as soon as I get somewhere, whether good or bad, to give an update as to haw it all came out.

Lyn