It seems that all the senior officers of Assad's army as well as the soldiers simply ran away. 

The rebels are making history today - a turning point in the Syrian civil war that began in 2011.

In the attached videos, the Syrian rebels are near the international stadium of Aleppo, as well as moving freely in many neighborhoods in the city. As mentioned, there is no fighting from the forces of Assad and his allies.

NEWSRAEL: Of course, having Islamists take over will not be good, but you all know what they say one should do when your two enemies are fighting each other...

Source: Abu Ali Express - Telegram