Here's one of those weekends where the L line will close totally in Manhattan and through much of Brooklyn. From Daily News, New York, NY, 9/12/19:
An L-pocalypse of detours are coming for riders on the subway line
L-pocalypse alert this weekend! The L train is out in Manhattan and much of Brooklyn and will only run between Canarsie and Broadway Junction from 10:45 p.m. Friday to 5 a.m. Monday.