An Airbus A321 bound for St. Petersburg, Russia from Egypt has crashed today in the Sinai Peninsula, killing all 224 aboard. ISIS and others are active in the area, but it's currently not believed that they had anything to do with it; currently it's thought to have been due to a technical failure.
It's odd because the most dangerous parts of any flight are usually takeoff and landing, but this occurred at 31,000 feet.