It seems that the Russian ambassador to Turkey was assassinated earlier today. Everybody is covering it, but here's a link if you can't find one.
Assassinating ambassadors is bad juju. Most countries don't take kindly to their diplomats being murdered. I'm sure that president Putin is meeting with his staff right now, figuring out a way to .... well... do whatever it is that Russia does.
Turkey may have just stepped on their collective tallywackers. Wars have been started over less than this, and even though Turkey is a NATO member, it should remember that Obama is still president and Kerry is SecState. Don't expect any help from the US.