If you want them to break at the same time, than control + click on both (so they are both highlighted), type control + T, go to func_breakable, and now they are all one entity.

Uba-Pook

Select both the brushes (the pillar and the thing above it) and tie it to an entity, func_breakable.

EDIT

teh pook 0wn3d meh!!

Oh hai.

Thanks, Looking at key values - I see explosion damage and radius. Is it also possible to use these?

Copy-cat lol

Edit:

Hamstah is a l337 mapper too :D

Uba-Pook

And yeah it is test things out, get what you want :D

Uba-Pook

You can also go into the func_breakable properites and do it on outputs.

Music Is The Answer.

I think you can use that too... but just do it our way :)

Oh hai.

I'm telling you dude, test around with both and get what you want its hard for us to decide lol

Uba-Pook

If you do it my way you can time out when it breaks also :)

Music Is The Answer.

I'll try both, What I'm trying to do - Is have a vent area above the pillar - So when the pillar breaks so does the floor