  We show that the Bel-Robinson (BR) tensor is - generically, as well as in its
original GR setting - an autonomously conserved part of the, manifestly
conserved, double gradient of a system's stress-tensor. This suggests its
natural extension from GR to matter models, first to (known) massless scalars
and vectors, then to massive ones, including tensors. These massive versions
are to be expected, given that they arise upon KK reduction of massless D+1
ones. We exhibit the resulting spin (0, 1, 2) "massive" BR.
