Red Sox/Orioles (4/25/15?); the next game there was played without fans allowed in (4/29/15).
Ferals were rioting in the city, and there was concern they’d set upon the fans.
Yes, I recall that the Orioles played a home game that was closed to the public, during the Freddie Gray riots. If I recall correctly, one or two games had been postponed, then it was decided to play an afternoon game, but closed to the public, so that the Orioles would have one less game to try to reschedule later in the season.