Nothing is known yet about why the plane went down. All passengers and crew were killed. It was flying from  Egypt to Russia.

Several planeloads of Russian specialists have flown to Egypt to take part in the search and salvage. The black boxes have been recovered. Officials plan to begin flying the remains of passengers that have been found back to Russia today.

Today, Sunday, is a national day of mourning in Russia for this tragedy.

Check RT.com for updates on the situation