Police said three men were shot during a fight outside Cowboys Dancehall on the Northeast side.
Officers were called to the popular nightclub in the 3000 block of NE Loop 410 around 2:45 a.m. Thursday.
Witnesses tell police it happened as two men were leaving the club.
"A truck with four males came up to the location, approached the two males in reportedly an aggressive manner," Sgt. Javier Salazar said.
A fight broke out, police said, and one of the men who was confronted managed to grab a gun from his truck.
Police said he fired at the group of four men and hit three. One was pronounced dead at the scene. The other two were taken to San Antonio Military Medical Center in serious and critical condition. All three of the men were shot in the upper torso.
Investigators are interviewing witnesses and those involved, including the alleged shooter, to determine what led to the incident.
"At this point, we're still trying to determine if there was any relationship between the two and the four prior to (the shooting) or if there was any sort of altercation inside the night club," Salazar said.
Police said the shooting could be considered a case of self-defense. The names of the people involved have not been released.