A large man -- who appears to be a bodyguard -- attempts to hold Solange back, but she manages to connect at least 3 times. At one point Solange throws a kick and Jay grabs her foot, but never attempts to strike her. Beyonce stands by without getting physically involved.
It's unclear what triggered the fight.
And this is interesting. When you look closely, you see the bodyguard hit the emergency stop switch on the 12th floor -- mid fight -- presumably to keep the fight private.
All three walked out of the building together -- Solange looks pissed -- but while Bey and Solange get in one car ... security walks Jay to a different one.