Bad hubs???

My 2003 Venture has a problem with its wheel hubs...at 11000 miles one went bad. 1000 miles later the second needed changed. Now, I've gone another 12000 and the first replacement is bad again. I expect I'll be back in the garage soon to replace the second replacement.
Asked the mechanic why these are going bad and he responded by asking me if I drive through lots of water....I don't.
Anyone know what's going on with this part? I'm concerned that a catastrophic failure could cause a wheel to fall off.

hitting curbs not that hard will cause pre failure. i know no one drives wrecklessly. also gm had several problem with the hubs in 03 mostly awd. the possibilty of the wheel coming off is almost impossible. never seen it from a bad hub with out hitting a median

What is going wrong with the hubs, do they start to growl or are you getting an ABS light?

You are not alone, I have a 2002 AWD Warner Bros. Venture. I just had the the car in for it's 7th front hub. You read that right too!! 7, 4 left, 3 right. Currently there is 47,500 miles on it. Dealer says they have been having problems with hubs. They won't look for other problems like bad motor mounts or axles. We usually get an ABS light followed by the AWD disabled light. We also have had some real bad bearing noises to start and then the lights start. The first let go at about 2800 miles, since then we have gotten anywhere from 3k -10k out of the replacements. This has been the biggest problem, we've had others but not hub related. It's basically been a $30,000 headache.