The text talks about the smugglers breaking into the catacombs some 40 years ago, and then bricking it up after being attacked by Erylium. This meant that Erylium was still trapped within the catacombs at that point. Nualia then re-opened the catacombs around 5 years ago.
Looking at the map, it appears as though there are two other entrances into the Catacombs - a tunnel into B3 and a tunnel into B6, although the latter also has a dotted line at the end suggesting the tunnel is a dead end. So are there three entrances to the Catacombs or only the one opened by Nualia?