But when the time of Ali's birth approached, his mother, Fatima Bint Asad, was asked to enter the Kaba. And this was not an accidental affair as if a woman was in the mosque and suddenly she was delivered of a child. She was expressly called to enter the Kaba, the door of which was locked. Some uninformed people think that Fatima Bint Asad was in the Holy Mosque when she felt labor pains, could not go out, and gave birth to the child. The fact was otherwise. It was the month of Fatima Bint Asad's confinement. She went to the Masjidu'l-Haram, where she felt labor pains. She prayed to Allah in the precinct of the Kaba, saying: "O Allah! I pray to you in the name of your honor and awe, to put me at my ease in this labor." Suddenly, the wall of the Kaba, which was locked, opened.

Another report says that a voice was heard saying: "O Fatima! Enter the House." Fatima went into the House of Allah in front of a crowd of people who were sitting round that place and the wall returned to its original condition. The people were greatly astonished. Abu Talib instantly came there and tried his best to unlock the door, but the door did not open. For three days Fatima Bint Asad remained inside the Kaba, apparently without sustenance of any kind. Both sects (Shias and Sunnis) agree that no one else had ever been given such distinction. 

And now after more than 1400 years the splitting of the Holy Kaba is obvious.

source : http://abna.ir