The day before the NFL was faced with its first coronavirus outbreak, Las Vegas Raiders players were seen not wearing masks at a charity event that was in violation of Nevada rules and NFL protocols.

A fundraiser for the charitable foundation of Raiders tight end Darren Waller on Monday night drew Derek Carr, Jason Witten, Nathan Peterman, Foster Moreau, Zay Jones, Hunter Renfrow, Nevin Lawson and Waller along with a crowd of about 100 to an indoor event at the DragonRidge Country Club in Henderson, Nev., a Vegas suburb, according to the Las Vegas Review Journal. Photos and video showed players and guests not wearing masks.

The country club was fined $2,000 by the city of Henderson on Tuesday for four violations of coronavirus directives issued by Nevada Gov. Steve Sisolak (D). Those directives included the wearing of masks and limiting indoor gatherings to no more than 50 people. (The latter order is set to be increased to a limit of 250 on Thursday.)

The league, which unlike the NBA and NHL is not holding its season in a competition bubble that keeps teams at a limited number of sites, set protocols in agreement with the NFL Players Association that limit players’ activities, including barring them from attending any event that “violates local and state restrictions.”

Raiders owner Mark Davis said the team would look into the matter. “We obviously take responsibility for this,” he told the Review Journal. “You don’t like seeing this. I don’t know that it’s actually been built into our memories that you have to wear a mask. Our organization takes it very seriously.”

The NFL had not commented on the matter as of early Wednesday morning.

One person who was at the gala told the Review Journal that Waller wore a mask throughout the event, but video showed Carr and players talking and with attendees without masks.

The NFL was confronted with its first outbreak of the coronavirus Tuesday, when three Titans players and five staff members tested positive for the virus after their game in Minnesota. The Titans shut down their facility and the Vikings suspended in-person team activities, including practices and face-to-face meetings.

The NFL, Titans and Vikings are proceeding as if the teams’ Week 4 games will be played. Tennessee has a home game against the Pittsburgh Steelers on Sunday and the Vikings are scheduled to play the Texans in Houston. Through the first three weeks of the regular season, the NFL did not have a game canceled or postponed because of the pandemic.

This isn’t the first time the Raiders have run afoul of coronavirus protocols. Coach Jon Gruden was fined $100,000, and the team $250,000 because of Gruden’s failure to wear his mask on the sideline the Week 2 game. The Raiders are also being investigated by the league for allowing an unauthorized team employee in the locker room after the game, ESPN reported. Gruden has said he had the coronavirus in July.