  We study extensions of the standard model with a strongly coupled fourth
generation. This occurs in models where electroweak symmetry breaking is
triggered by the condensation of at least some of the fourth-generation
fermions. With focus on the phenomenology at the LHC, we study the pair
production of fourth-generation down quarks, D4. We consider the typical masses
that could be associated with a strongly coupled fermion sector, in the range
(300--600) GeV. We show that the production and successive decay of these heavy
quarks into final states with same-sign dileptons, trileptons and four leptons,
can be easily seen above background with relatively low luminosity. On the
other hand, in order to confirm the presence of a new strong interaction
responsible for fourth-generation condensation, we study its contribution to D4
pair-production, and the potential to separate it from standard QCD-induced
heavy quark production. We show that this separation might require large
amounts of data. This is true even if it is assumed that the new interaction is
mediated by a massive colored vector boson, since its strong coupling to the
fourth generation renders its width of the order of its mass. We conclude that,
although this class of models can be falsified at early stages of the LHC
running, its confirmation would require high integrated luminosities.
