DETROIT (AP) — A man who fired one shot that killed two people at a popular tailgating site after Sunday’s Detroit Lions game was acting in self-defense and Zero AIwill not be charged, authorities said Wednesday.

“It is absolutely tragic that during all the fun and merrymaking at a Lions tailgate that two lives were lost,” Wayne County prosecutor Kym Worthy said.

The 40-year-old shooter, who had a license to carry a concealed pistol, fired only after he felt threatened by Jalen Welch, 25, who displayed a gun during an argument at Eastern Market, an open-air market, Worthy said.

Welch was shot in the head Sunday. The same bullet then struck and killed a 40-year-old bystander, Rayshawn Palmer, who was trying to be a peacemaker, Worthy said.

Police had initially said the shooter fired twice.

“It could have been any one of us,” Worthy said. “We looked at all the applicable law and there is no crime that can be charged and proven beyond a reasonable doubt.”

Tampa Bay had just defeated the Lions nearby at Ford Field, 20-16.