Of course they dared. That's why they are called adventurers.

They descended the earthen ramp, and astutely observed that they were not alone. Indeed, for as far as the eye could see (and as they learned, much further, since it was pretty dark in there), animated corpses were stirring.

Wisely deciding that discretion is the better part of valor, the party backed up. Most of the party, that is. The brave-but-not-so-wise rogue, still nursing his sprained ankle, decided that he'd make a quick swipe at a nearby grave. That's why they call him a rogue.

A quick swipe he made, but that seemed to get the attention of the nearby undead, who hadn't paid much attention yet. He scrambled up the ramp, but was unable to make an escape, and the undead closed in on him menacingly. Fortunately for the rogue, just as the undead were about to recruit him into their ranks, the barbarian (?) charged in, threw him over her shoulder, and raced back up and out of the chamber of death.

The cleric realized that with the proper application of positive energy he might be able to reforge the broken seal. Unfortunately, he didn't apply the positive energy properly, so they instead they piled up the table and some heavy items from the previous room, which they thought might hold the undead at bay long enough for them to walk away and pretend that nothing had happened.

So... that's just what they did. They checked the last couple of chambers to see if there was any loot they could pillage, and then noticed that the storm had subsided, so they went back to town.