I was at a convention all weekend, so I wasn't able to talk about this.
Anton Yelchin, the second man to play Pavel Chekov, was killed in a tragic accident when his jeep, which was apparently not in park, rolled backwards over him. There are indications the accident was caused by a faulty gearbox (similar models had been recalled).
The rebooted movies had their flaws - but Yelchin's performance was not one of them (And to be honest, the flaws were pretty much all at the writing and directing level, not the acting). He was only 27 years old - and everyone in the Star Trek community mourns.