From HGWiki

The statues in this area give colossal divine AoE damage (1000 points!) when broken and the constructs use Cone of Cold which if it hits them will cause them to break. Use ranged damage (Ice Storm amulets from the merchants are effective) to clear the statues in groups of two before progressing to the far end of the room, one of the guardians drops a key allowing access to the Tunnels of the Underdark. The statues respawn at an alarmingly fast rate and if you take too long to progress you can find them respawning behind you as you are progressing down the hall.

Rest Spawn Chance

Zero

Creatures

Exits

• Halls of the Dead
• Tunnels of Underdark