the choir outbreak is consistent with a growing body of evidence that the virus can be transmitted through aerosols — particles smaller than 5 micrometers that can float in the air for minutes or longer.https://www.latimes.com/world-nation/story/2020-03-29/coronavirus-choir-outbreak
...a study published March 17 in the New England Journal of Medicine found that when the virus was suspended in a mist under laboratory conditions it remained “viable and infectious” for three hours — though researchers have said that time period would probably be no more than a half-hour in real-world conditions.
...it’s possible that the forceful breathing action of singing dispersed viral particles in the church room that were widely inhaled.
...some people happen to be especially good at exhaling fine material, producing 1,000 times more than others.
Amateur singers interested in choral music tend to be older, but the group includes some young adults.
...The youngest of those sickened was 31, but they averaged 67