They drop their acorns in fall and leaves in spring and sprout new growth immediately after the last frost of the season.
They don't do well in urban settings and they are not hardy beyond USDA Zone 8 except under pristine growing conditions.
Those trees have been dying a slow death since they started pressure washing them. That corner and that setting is nowhere near "pristine."
While I share Drewy's sentiment regarding Harvey Updyke, all he really did was shove those trees over a precipice they were inching towards since fRan was our coach.