This quest seems to be a bit deceptive. It mentions the "eastern bridge", but doesn't tell you that it is referring to the bridge directly north of you.

About half-way over the bridge, there are two doors on either side leading down to a lower level. He's on the 3rd level down on the east side. He's a corpse, so look on the ground.

Cross the bridge heading north into Arathi (51,8) and turn right. Head down the winding stairs and the corpse is on the ground.

As soon as you click it, Dwarves will spawn and chase you out.

Basically, I would say that this quest is labeled as [Elite] since the mobs that you encounter are elite. I firmly believe that this quest is doable without dying by any class at the level the quest is acquired. Solo. Here's how:
Go north from Dun Modr and across the bridge until you reach the archway with the doorways. Use the eastern one. Run down the steps into the main room. There is another set of steps go down these. With any luck, you won't aggro until you get to this lower level. Run to Ruslocke's corpse, I think it's on the west side of the room. Investigate and quest accept ASAP. Chances are, mobs will be pounding on you.
This room has two exits on the level you're on, one right next to the corpse. Run out it. You are on a balcony. Make like 007 in Goldeneye and dive. You'll hit the water, safe and sound. NE of the bridge is a climable bank. You can then sprint past mobs and get back to Dun Modr. Incidentally, since you'll be coming right back up here to blow up the cache of explosives, I highly recommend approaching it from this side as the mobs can be pulled in smaller groups from this path.
I did this with a level 28 Hunter. Perhaps leather armor and a pet are essential parts of this strategy. Let me know.

Edited, Sun Aug 21 18:35:06 2005

51,8

It's the bridge between wetlands and arathi, about the middle of the bridge you'll see a doorway, go down get body, I just jumped down (30 mage) used mana shield, nova'd and left