Concerning the Dormition of the Theotokos, this is what the Church has received from ancient times from the tradition of the Fathers. When the time drew nigh that our Savior was well-pleased to take His Mother to Himself, He declared unto her through an Angel that three days hence, He would translate her from this temporal life to eternity and bliss. On hearing this, she went up with haste to the Mount of Olives, where she prayed continuously. Giving thanks to God, she returned to her house and prepared whatever was necessary for her burial.
While these things were taking place, clouds caught up the Apostles from the ends of the earth, where each one happened to be preaching, and brought them at once to the house of the Mother of God, who informed them of the cause of their sudden gathering. As a mother, she consoled them in their affliction as was meet, and then raised her hands to Heaven and prayed for the peace of the world. She blessed the Apostles, and, reclining upon her bed with seemliness, gave up her all-holy spirit into the hands of her Son and God.
From the Greek Orthodox Archdiocese of America website. To read more, go to the Online Chapel – August 15th.