Topic says it all. Mostly razorwings in the second room of Into the Dark.

As far as I remember yes, they just can't end their movement on top of the rubble.

Big Remy said:

Agreed. There are almost no restrictions on Interrupt attack timing.

Nope, you will not be able to trace LoS when the figure is on a space with rubble. Above water should not be a problem though.

Siebeltje said:

So you are claiming that an obstacle blocks LoS to it's own space?
Sorry, doesn't wash. Under this reasoning every figure would block LOS to the space it is in. Remember, attacks (and explictly LOS, see step 2 of attacks) target spaces.

The LoS rules only work if LoS is not obscured by anything in the space being 'seen to'.

I am still certain that you can target an interrupt attack at a figure moving through rubble (assuming no other LOS blockage).

Yes, I agree.

For example, trees. Trees block LOS but you can attack a figure standing in a tree. If you couldn't trace LOS to it (and yes I know they grant Shadowcloak and you can only hit with a melee attack, blah blah blah), then you'd never be able to hit a figure in a tree space. No significant difference between that and the rubble really in terms of LOS.