Cause of South Korea plane crash unclear as officials focus on bird strikes
Cause of South Korea plane crash unclear as officials focus on bird strikes

www.theguardian.com
Cause of South Korea plane crash unclear as officials focus on bird strikes

Cause of South Korea plane crash unclear as officials focus on bird strikes
Cause of South Korea plane crash unclear as officials focus on bird strikes
From the Wikipedia article, it sounds like a combination of factors. Huge number of birds, potential landing gear issue, and very short time between emergency and impact.
I see some armchair analysis over on reddit (https://old.reddit.com/r/aviation/comments/1hoky8v/video_of_jeju_air_flight_2216_shortly_before/) but really we'll have to wait for the investigation to know exactly what happened.