You can't think of any scenario having one controller makes sense?
I don't think people saying this stuff quite understand how busy LGA is even at night. I'd even go as far as to say that three minimum on duty with two in the tower at all times (for a ground/air split), would be the bare minimum for any hour or situation at LGA.
However, arrivals stay pretty heavy right up until 23:59 even on schedule and if you've got a lot of delayed flights (not exactly uncommon at LGA) - you may still have a lot of departures going out in the 23:00 hour.
I would not be surprised to learn that they're staffed to an appropriate level for what the schedule says is supposed to be operating at that time, but a very inadequate level for what actually winds up operating at that time on many days.
Initial analysis suggests they were running about 75% of full capacity in flight ops in the 15min prior to the accident. I doubt they were staffed to 75% of the daytime peak.
La Guardia appears to handle 400 flights a day, 22 an hour. I see 6 moving planes right now (https://www.flightradar24.com/airport/lga); hopefully they have more than one person on?
At one of the nation's busiest airports? Where there are two intersecting runways, both potentially with departing and arriving aircraft? Nope.
But, sure, a single-runway regional airport can probably get by with a single controller.
Here it's being done at SFO or so it seems: https://data.ntsb.gov/Docket/Document/docBLOB?FileExtension=...
While searching I did find this other document where a GC (LC appears to be Local Control for local air traffic and GC is ground control) controller complains about combining due to short-staffing https://data.ntsb.gov/Docket/Document/docBLOB?ID=19837915&Fi...
Well, it'll be an interesting report from the NTSB at least.
Looking at the normal schedules - if all is on schedule there'd be no departures in the 23:00 hour but you'd still have the arrivals side running pretty heavily. However, once you factor in things not being on schedule, as they evidently were not on that night, you get:
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The 15min before the accident had 14 flight operations (per Juan Browne/blancolirio going through the ADSB playback). And that's in marginal weather and at night, which makes things more complicated.
That is 75% of the official maximum capacity of the airport - during the main part of the day where there's government-imposed caps on flights, it's capped at 74 operations per hour or about 18.5 per 15min.
As such, it seems apparent that you would need just as much staffing (or at least 75% as much) at that time to safely handle the traffic volume that was occurring that night as you did in the main part of the day.
Unless the normal staffing here was just 2 people, it seems clear that 1 is inadequate.
What we are seeing here is the normalization of deviance.