It must be a military base. At retreat, everything stops. Bats and balls are stilled, laughter is quieted and children, and all others, stand with respect. When my dad retired, that was one of the things I missed the most - that and wheeling my bike down to the parade grounds on Saturday morning to see the troops in formation.
USAF did the same thing in the 1950's morning and night when the flag was raised and when it was lowered. Used to do that before it became the custom to nail it onto the sides of buildings and make t-shirts with flags on them. My allergies were bothering me as well.