RAID 5 failure

I just had two disks go down on me within 48 hours. I was using an Escalade 6800 IDE controller, with three drives set up in a RAID 5 configuration. I got a notice on Thursday afternoon that one went dead. I immediately did a backup, and swapped out the drive that night. I couldn't get the array to rebuild, however. After upgrading firmware and trying the rebuild a half-dozen or so times, I noticed that there were many errors on one of the other drives on the array. I couldn't fix these with chkdsk /f (that's all I had - anyone have suggestions for better software, I'm all ears!). Saturday morning the other drive finally died alltogether. I got some brand new drives, and still couldn't rebuild the array. Fortunately, I was able to fit all the data on one large drive and mirror it, so I only had one day of downtime during the week (let's hear it for good backups!)
Has anyone else had two drives die in such a short period? Anyone have any tips on how I could set up better? Any horror stories?

We had a similar problem recently but it turned out to be the RAID controller causeing write errors rather than the drives being bad. Are you sure it was the drives that were bad? Its running ok now on the same controller?

I have a suspicion that the card could possibly be at fault, but I'm not sure how to check. I do have drives working on it now, but no RAID. I just seems that the odds should be against having failures that close!

This may not fit your situation exactly. But power is so important with raid arrays.

If the RAID card still seems to be functional (say, in another system), if the drives still seem to work (say, after writing zeros and repartitioning), and if all you have really experienced is corruption of the array rather than true electrical/mechanincal failure of the drives, you might also try looking at your power supply/source.

How many hard drives? How many CPUs? How many fans, including the little ones in hot swap drive bays, etc? How many adapter cards?

What wattage power supply? What quality? Is there a UPS to isolate the power supply from spikes and brown outs?