Actually, I'm told they may me ilex shrubs which aren't very drought tolerant so may be I did kill them with lack of water...

Did you check for bugs? We had to spray for scale several times this summer. We just moved to Richmond from the Midwest and landscaping care is just a bit different, including keeping things more watered. We run the hose on a slow trickle once a week for 20 minutes on each tree and bush and it really helped everything stay healthy over the summer.