Heads up here. We tried for this achievement for three of our guildies the other day. We were very careful to not break any of the ice tombs. He died while one of our party members was still entombed. Our best guess is that there is a bug that causes that to count as breaking one because our guild mates did not get the achievement. We all turned in a ticket. The GM said they had gotten several complaints (not sure if he was just looking at ours) and were investigating it. We were all on Teamspeak, everyone avoided doing any AOE's, etc. so we are positive we didn't break any.