[Video] Beyonce’s Sister, Solange, Violently Attacks Jay Z????

TMZ has obtained a surveillance video of Solange kicking and swinging at Jay Z in an elevator.  Sources say it it all happened at the Met Gala, but the reason for the fight is unclear.

Surprisingly, Beyonce stands by and watches the attack in the beginning but then eventually steps in when Solange attempts to go in for a second round with Jay Z.

Check out the surveillance footage below:

Jay Z PHYSICALLY ATTACKED by Beyonce's Sister Solange - Watch More Celebrity Videos or Subscribe