Some elaboration is in order. In 4e, you're lucky to see a non-daily attack do 20 points of damage, even at paragon levels. OTOH, hit points often top 100, even at heroic levels. Add into that the rather high whiff factor in 4e, and you've got a recipe for grinding, not brisk three-round battles.
Okay, let me try and go through each round as well as I can remember:
Pre-combat: Fighter, Rogue, and Wizard head in from the north; Warlock and Warlord head in from the south.
Surprise Round: Elf Scout dumps boiling oil on Fighter, Rogue, and Wizard via murder holes; misses everyone except the Wizard, who takes (3d8+4 = ~21) damage.
Round 1: Wizard goes up on balcony, opens pit.
Elf Scout 1 opens door, stabs Wizard.
Elf Archer, Elf Scout 2, and goblin minion show up through another door. The Elf Archer might have dropped the Wizard, while the scout went after the warlord/warlock.
Cave Bear comes up and melees fighter (the only one he can reach).
Warlord blasts them all with a Fire Shroud, killing the minion and destroying the rickety balcony they are standing on. (Damage is 10 to all, 2 more to the elves, ongoing fire 5.)
Fighter Tide of Irons the Cave Bear back into the pit. (Damage is 21; the pit is 20' down.)
Rogue - ?? Hits the bear for 16 damage?
Warlock does something... might miss.
Round 2: The Wizard Thunderwaves the Elf Scout off the balcony. Damage is 17.
Elf Archer shoots Wizard, drops him.
Elf Scout 2 attacks the Warlord?
Elf Scout 1 attacks ??
Bear gets out of pit and attacks the warlord?
They all fail to save vs. Fire.
I can't remember what happened past this round, but the PCs are obviously able to deal enough damage to bring down monster HP quickly - all the elves had taken 17 damage after 1 round of PC attacks! I think only one Elf Scout survived to the next round.
The bear survived, not quite Bloodied yet, but it was on a chain and the PCs didn't want to fight it. That's when the goblins showed up.
edit: The bear didn't save against the fire, even with the save bonus, until late in the game. So it started off taking 10/20/31/40/56/60 damage, and then 65/70. I think I forgot to add the fire damage in one round and I am adding two rounds worth at that point. So in the first round the bear's taken 31 damage, in the next two it has taken a total of 70.
Plus all the elves are dead; their damage looks like this:
Scout 1: 17/22/29/dead
Scout 2: 10/12/17 - that damage is 10 from the fire shroud, 2 from falling, and 5 from ongoing 5 fire - 29/41 (obviously dead at that point)
Archer: 10/12/17 - that's fire damage, and I think it dies after that from a Sneak Attack.
The bear's damage: 82/87 - that's probably one more round - 97/101/113/118 - another round - 130/151/164/dead. It probably saved around the 118 mark and lasted about 2 rounds after that.