They were indeed the only controller, working both ground and tower frequencies.

> I'm not sure if they were the only controller working at the time, they continued working after the incident which seems unusual; my understanding is normally they'd be relieved by another controller

I remember late last year, couple of months ago, US ATC controllers were without pay but forced to work anyways (similar to TSA I suppose, although I don't think they were forced, but volunteered to work without salary), is that still the situation? Couldn't find any updates about that the situation been resolved, nor any updates that it's ongoing, if so though it feels like it'd be related to the amount of available controllers.

Utterly unqualified to suggest any causes (wait for the NTSB report on that), but couple compounding factors I've read elsewhere to begin to understand the situation and context:

- Another plane was out of position, grabbing some attention of the controller

- Stop communication was ambiguous about whether talking to previous plane or firetruck

- The colliding plane didn't have "explicit" landing clearance, but a "follow previous plane and land the same way unless told otherwise" implicit landing clearance. In Europe, planes need an explicit landing clearance, the act of granting it may have brought attention to the runway contention. US implicit system (arguably) is a bit more efficient, debate will now be is it worth it (pilots are now required to read back instructions because of past blood... will this result in same thing?)

- This was around midnight and apparently a little foggy, making visual contacts harder

Remember folks, disasters like this are rarely caused by a single factor. NTSB reports are excellent post-mortems that look at all contributing factors and analyze how they compounded into failure. Be human here.

I’m always staggered by how stressed and tbh (not necessarily their fault given the circumstances) unprofessional US ATCs sound.

Sharp contrast with Europeans