The circumstances of his death were clarified in Fast & Furious 6. Jason Statham's Deckard Shaw killed Han. Now those events have been clarified even more in F9, thanks to returning director Justin Lin. As it turns out, Han didn't die at all.

How did Han survive the crash?

There's been one question that's been plaguing fans' minds since they first realised Sung Kang is returning as Han in Fast 9. How did Han survive? ... It turns out that Han faked the crash with help from Mr Nobody in order to get him out of harm's way. They'd met through Gisele who had also been working for him beforehand.

Why did Decker kill Han?

Deckard sought to avenge his brother Owen, following his defeat at the hands of Dominic Toretto and his crew, and thus seemingly killed Han Seoul-Oh, an action he later came to regret.