the U.S. air traffic control system has been chronically understaffed for some years now. this may be one of the contributing factors in Air Canada flight 8646's crash into a fire truck at LaGuardia which killed both pilots. the NTSB investigation will decide if it was.
https://www.cbc.ca/news/world/laguardia-airport-air-traffic-control-midnight-shift-9.7142856

ANALYSIS | Were 2 enough? Experts question number of air traffic controllers during LaGuardia midnight shift | CBC News
Following the deadly collision between an Air Canada jet and a fire truck on the runway at New York City's LaGuardia airport last week, concerns have been raised about whether there was adequate air traffic control staffing that night.