Kong had just thrown the sailors into the ravine who were on the tree. From what I have heard giant spiders go after them and finish them off.
Personally, the scene where the guy climbs up the tree to get away from the dinosaur gave me nightmares for years, that and when King Kong breaks through the giant door.
There’s a ‘recreation’ of that scene on YouTube...put together by Peter Jackson; who helmed the most recent ‘Kong’ remake...it’s really quite good...good for nightmares. :-)