Eddie's Con save: 20

Used to the loud noises of crowded farmer's markets and hawker's centres, the booming shockwave of sound does not seem to impact Eddie as much as he initially expected.

Con Save for Sully of DC 13: 13.

Thunderwave damage: 5

Quote from leapingmountain >>

Thunderwave damage: 8

 Since everyone saved, 1/3 damage, so 4 h.p.

A loud rushing noise fills the tunnel. Suddenly a huge wave of water fills the tunnel and heads towards the tunnel entrances, pushing everything in its path out.

Sully, after climbing up to the bridge. is safe from the water. He spots a couple of goblin bodies being pushed toward the exit by the water.

Eddie, and Kae, in their attempts to escape, find themselves in the path of this flood. 
Dex save DC 10, or be pushed out the entrance by the flood. 

Dexterity Save: 17 (15 + 2)

Kae really books it for the canine cavern, using the explosion's concussive blast to her advantage to push her even further.

Eddie’s Dex save: 18

Kae leaps into the wolf kennel area and avoids being swept away by the flood.

Eddie finds a nitch in the side of the tunnel that allows him to cling to and the flood of water passes him by. 

Sully watches as his friends find a safe place to avoid the swift current. 

After 5 minutes, the flood subsided just as fast as it had started. 

Actions?

"Well, now it's personal," Kae says under her breath as she marches back to the others. She climbs up the rope that Sully hung down, and encourages Eddie to do the same. If everybody's there, she'll try to nudge the party towards going around in the opposite direction of the bridge. "Maybe they'll think we're dead and we can get the drop on them? Anyways, even if they're expecting us it makes more sense to hit 'em from behind." Her plan is to not make much noise while walking, but her armor clearly has other ideas.

Stealth: 8 (5,4 + 4)

Eddie will climb up the rope to join his friends. “I think it’s time for somebody to get the smack down. This is a genuine Gucci knockoff and they almost got it wet” he says as he brushes droplets off his green ?leather? jacket.

All three party members make it to the overpassing bridge. With the combined weight of the party the rickety bridge sways and creaks when anyone moves. 
They find the bridge connects to a second tunnel that runs from northwest to southeast in direction. The tunnel is not illuminated but with Sully's blessing, everyone can see fine in the darkness.
The passage to the northwest runs 30 ft. then turns to the west and the party can not see further than that.
The passage to the southeast runs 20 ft. then turns slightly north and the party can not see beyond that point.
Actions?

"We were heading North before the water came rushing down. I'm going to try going down this eastern passage and see where it leads. I'll try to be quiet this time guys".

Eddie tries to move stealthily down the eastern passage until ti turns towards the north. When he reaches that point he will press himself against the wall and lean only his head around the corner slightly until he can see the passage.

Stealth Check: 11

Perception Check: 6

"Aight dude. Just be careful. Not sure if the gobbies got caught up in that as well, but better safe than sorry." Sully assured Eddiealong with a pat on the shoulder. "But, uh, we'll be right behind you at least a little ways. 'cause hanging out on this bridge is prolly not the best thing, ya dig?" He said with a bit of a smile to his voice, and would proceed to follow Eddie at least 10ft into the eastern passageway before leaving him to his scouting. 

In the meantime, he'd keep an eye on the west, and again switch to his crossbow in place of a shield and bat just in case any goblins came to check out the noise from that angle.

Stealth: 10.

Perception: 12. 
For keeping watch on the west half of the bridge.

That last stealth roll should've been disadvantage, so that's a 6 on stealth for Sully.

Eddie moves quietly down the passage (he hopes). He gets to the corner and does a quick look. He sees it as a much larger area but doesn't get any details of the room. He hits the back of his head against the stone tunnel wall as he does his quick peek. Not enough to cause much damage, more to give him a bit of pain and his eyes to swim slightly. 

Sully switches to his crossbow and watches the western part of the passage. He doesn't see anything but hears Goblin voices arguing in hushed tones coming from that direction. 

Eddie heads back towards Sully and Kae, before whispering "There's a room of some kind up ahead but I couldn't get a clear look to see what's happening in there. We should probably check it out?".

Kae gives a thumbs up. "Sure thing, Eds. Sully, maybe you should lead the charge. I mean, you're the one with the bat, and you've got those elven eyes." She'll go down the same path that Eddie tried to scout out, preferably behind a cleric or two.

Stealth: 14 (15,10 + 4)

Sully gave a loose thumbs up, but kept his crossbow trained across the bridge for a few moments more, squinting into the darkness. "Yea... yea we got goblins across the way from what I can hear as well. Plenty of'em too, arguing with each other over something or other. But can't quite make it out." He quietly warns Kae and Eddie, then set about once again shuffling his gear about until he once again wielded a bat in one hand and a shield in the other. "They'll probably be at it for a bit, so we got some time at least. Let's check out this room of yours. Stay on my six."

Sully rolls his shoulders, and on the back of a prayer he took up point in trying to creep into the room found by Eddie at least 10ft ahead of the party while keeping the wall to his immediate right for as long as possible.

Stealth:(4)23.