The plane suffered an engine mount failure, which tore a hole in the wing, sprayed shrapnel into engine 2, which caused a compressor stall reducing thrust past the survivable level. Then it crashed into a fuel recycling plant with a full load of jet fuel.
The scary part of the mount failure is that the mounts cracked in an unexposed part where visual inspection did not reveal the damage. It wasn't due for a teardown and inspection until it had traveled 25% (80% of the maintenance window) farther. That's why they grounded the entire fleet.
Takeoffs are dangerous because they run the engines hard, and parts are operating in the supersonic range.