I remember that night. I was following the NBA on ESPN, maybe the "Heat" were playing, I don't remember, and one of lead stories was the postponement of the game in OKC. The media had no information at first. I remember there being some chatter that it was a delay and that the game might resume but that is belied by the video that those screen grabs were taken from--the PA guy tells the crowd to leave and says they are "safe." He didn't give a reason. Bomb threat? I think that was also a fleeting theory.
That was, I think, the first time that the seriousness of the coronavirus entered my consciousness.