USC Frat Sued In Death of Cal Soccer Player

The family of a 19 year old USC Berkeley soccer player who died in March claims he was illegally served booze at a USC frat party hours before his death ... this according to a lawsuit obtained by TMZ Sports.

The freshman soccer player, Eloi Vasquez, was killed as he tried to run across the 10 freeway sometime after 2 in the morning on March 28th ... and now his family is pointing the finger at the Tau Kappa Epsilon fraternity.

In the lawsuit, Vasquez's family says he was allowed into a party at the TKE house even though he had no I.D. -- but the people at the door knew he was likely under 21.

Still, the family claims he was not only served a ton of booze -- but the frat and other party organizers failed to take care of Vasquez when it was obvious he was hammered and unable to care for himself.

Vasquez reportedly left the party around 1:30 AM and somehow got to the 10 freeway -- where he was struck by a car and killed.

The family is suing the entire student executive board of TKE -- from the president to the social chair and even the treasurer -- along with USC and others they believe had a role in the party.