The first ,most dangerous and likely aspect is not AI actually killing us but growing too much dependent on technology. Tech can fail. A user can not just change a tech system, we are in the situation that human judgement has no part of the working process, essentially tech make the rules. It is not just a matter of hiring a programmer/engineer to make change to the tech, your tech has dependencies on other tech you don't have control on, when a tech which many other tech depended on it cause a lot of damage. It is not even science fiction, once the new browser/OS/standard make the tech you are dependent on obsolete, your tech die, such as what happened with flash games/apps and flash player, such as what might have happened to this forum(dependence on obsolete software). This is just a small scale example, once we have AI there will be much more damaging result, like the "Black Monday" stuck market crush that happened due to programs(bots) stocks trading.