TMZ released security video today of Beyonce’s sister Solange attacking Jay Z in an elevator at the Standard Hotel after the Met Gala. The Knowles sisters enter first, followed by Jay Z and a bodyguard. In seconds Solange is seen getting in Jay Z’s face and then violently hitting him. The attack escalates as Solange attempts to kick her brother-in-law and has to be restrained by the bodyguard. Jay Z remains completely calm during the attack and does not retaliate. Beyonce exhibits similar behavior, standing in the corner only to adjust her dress. She attempts to intervene at one point but the bodyguard appears to have a firm hold on Solange. After they exit the elevator, Beyonce and her sister rode in a different vehicle than Jay Z. No reports have emerged as to what triggered the attack.