The dwarves fought hard and they fought well. As soon as Gandalf gave them an opening, Kili retrieved his weaponry and fought alongside of his brother and uncle. Some goblins were kicked, some were shoved, others were beheaded and stabbed. Kili narrowly missed being shot, but he thought quickly and used a ladder in order to push off many at once. "There's too many of them!" 
The bridges swayed dangerously, but they made it to the final platform. This was the only path that lead outside.

As they attempted to cross, the Goblin King suddenly broke through from underneath and pulled himself up onto the bridge in front of the Company. At the same moment, hundreds of goblins approached them from all sides. 
"You thought you could escape me?" The Gobin King stepped towards Gandalf, mace in hand, then brought it back to swing. "What are you going to do now, wizard?"

Kili and the rest were witness as Gandalf hit the king in the eye, and then he sliced his middle clean open. After a brief pause, the Goblin King looked to his wound, then back to the group. "That'll do it."
His weight caused the bridge to start shaking, and the section of the bridge on which the company stood broke away from the rest of the bridge and started to slide down the side of the cavern at an alarming pace. Everything was demolished on the way, and there were plenty of yells and screams from varying members.
The bridge slowed just in time, breaking apart and burying the dwarves in the timber and wood. 

Bofur blinked in surprise, his heart rate never slowing. “Well, that could have been worse.”
Suddenly, the heavy corpse of the Great Goblin lands on the wreckage, squishing the dwarves further. A few cried out and groaned in pain. Dwalin attempted to push some timber off of himself, Kili close by. “You’ve got to be joking!”
Still a bit dazed, Kili started to push himself up, but he was covered with rubble. The sight he was met with was alarming; hundreds of goblins were crawling their way.