On October 31, Metrojet flight 9268 departed from the city Sharm el-Sheikh of Egypt, and was heading to St. Petersburg, Russia. The Metrojet disintegrated over the Sinai Peninsula, and all 224 people aboard were killed.
At first, the terrorist theory was quickly excused, and mechanical failure became the popular belief. Though both Egypt and Russia agree that it is too early to draw conclusions, President Obama announced that there is a "possibility" that a bomb was placed on the plane by a terrorist group. One official even claimed that it was "99.9% likely" of this tragedy was a result of terrorist groups, such as ISIS, which is another leading theory.
Security cameras are being reviewed, in case of spotting something suspicious. Meanwhile, security checks were conducted at the airport, with many flights delayed. British military officials are currently investigating the 'accident', and agree that it is "highly probable" that a terrorist group got a bomb onto the plane.
The two main theories suggest that this either was or wasn't an accident.
Read more here

What do you think happened, and do you believe this was an accident? Why or why not? If you disagree with these theories, do you have any of your own?
Replies
You probably should have explained the theories within your summary. This is also a story that was done last week.