The 19-year-old, the number one pick in last month's National Basketball Association draft, scored 11 points in Las Vegas before he went off with a knee injury in the first half.
Live footage of the moment the natural disaster struck was captured live on ESPN as the NBA's Summer League showcase was going on during day one.
There had been two sellouts in NBA Summer League history in Vegas before Friday. And Las Vegas won't be any different.
The Knicks, at 8-1, are the favorites to win the Las Vegas Summer League championship at Caesars Sportsbook. "And Zion loves the game".
Immediately after it seemed like Zion was stealing the show, Barrett scored the first professional points of his own with a 3-pointer followed by an and-one layup.
The Pelicans PR staff later said, the injury came after knee-to-knee contact, and wasn't expected to linger - the organisation understandably taking a cautious approach.
There were seven minutes 53 seconds left in the game when it was stopped.
A game between the Orlando Magic and San Antonio Spurs inside the smaller Cox Pavilion, which is attached to the Thomas & Mack Center, initially continued without delay because that gym lacks an overhead scoreboard.
Before he exited the game on Friday night, Williamson poured in 11 points in just nine minutes in the first half of the game. The NBA said a survey was completed by two separate independent structural engineers on Saturday, which determined the facilities were safe.