To pull the supports out from under it similar to imploding it is not what it means, that sounds good, but here is what it means.
The demolition process uses explosives to damage the columns. This explosion, like any, is a sudden expansion of gases. That expansion, when over, leaves a vacuum. The vacuum within the building "pulls" the building into the middle, helping it to implode, not explode all over the surrounding area.
When a bld is demo'd they might say, "pull it", to mean create that little black hole to suck the build into.
The pulling action also helps the building to fall faster than it would without assistance.
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What does it mean to pull a building