In theories with extra dimensions, the SM is confined to a brane in a higher dimensional space. Then the fundamental Planck scale, the energy for strong gravity, can be as low as 1 TeV, raising the possibility of probing strong gravity at high energy colliders, such as the LHC. In particular the Thorne hoop conjecture, and recent numerical/theoretical studies suggest particle collisions could produce black holes.  A paramount open question is: how much gravitational radiation is emitted during the collision. A method, which agrees with numerical relativity in 4 dimensions, models the ingoing particles as gravitational shock waves. We have extended this method to higher dimensions in first order perturbation theory, with striking results for the inelasticity: it fits the remarkably simple formula 1/2-1/D.