[matt1234]

The bomb may have been placed in the tree well.

The picture above (and at post 56) shows 2 investigators kneeling next to a "tree well." A tree well is a gap in a concrete sidewalk that allows a tree to grow. In this case the gap is rectangular. The well is commonly covered with a steel grate (at sidewalk level) with empty space below to allow for drainage. In this case, a rectagular grate is in two sections. One section has been removed and is on the sidewalk behind the right-hand kneeling investigator. The other section is still in place.

Many tree wells contain drainage pipes, electical junction cavities, or other crevices that could contain a bomb.

[gore_sux]

Yes I just noticed in #56 that they have half the grate that goes around the tree pulled up and it is sitting behind the guy with the yellow boots so the bomb may well have been under the grate. I would think that would have greatly suppressed the damage of the bomb but also explains the horrific leg injuries if it was below people standing over it.

[Obama_Is_Sabotaging_America]

Wouldn’t the grate been blown up, out and away from the explosion? Or are you saying the bomb might have been temporarily stowed away there?

[DouglasKC]

Many tree wells contain drainage pipes, electical junction cavities, or other crevices that could contain a bomb.

Could be that they are looking in there for forensic evidence of the bomb that may have fallen into the grating.