If a tree falls over in a forest, and nobody is around to hear it...

[Stekkmen]

how do you guys reckon the tree fell over in the first place? Rotted roots? Maybe lightning, or a wild fire?

[Kaga]

Probably the roots. A fire would've been more likely to attract attention.

[mdk]

Mass extinction event, followed by wind.

[Gwazi Magnum]

Tree's are capable of rotting out and dying on their own.
It probably just reached the tree equivalency of old age.

Or something damaged it beforehand and it just now gave out from the lack of support.

[Shanks]

It dropped its keys and fell over trying to pick them up.

[Brovo]

It fell over when a bigger tree fell on it.

[Cayden Black]

Timbersaw did it!

[Protagonist]

Well, there could be a deaf logger. It is also possible that there was a long drought and the tree died. Or maybe the tree got sick. It may even have just died of old age, but that's not very likely (trees can live for a very, very long time).

[Cpt Toellner]

Welcome to the new Off Topic ladies and gentlemen.

[Foster]

Soil degradation.