  Baryon resonance production in proton-proton collisions at a kinetic beam
energy of 1.25 GeV is investigated. The multi-differential data were measured
by the HADES collaboration. Exclusive channels with one pion in the final state
($np\pi^{+}$ and $pp\pi^{0}$) were put to extended studies based on various
observables in the framework of a one-pion exchange model and with solutions
obtained within the framework of a partial wave analysis (PWA) of the
Bonn-Gatchina group. The results of the PWA confirm the dominant contribution
of the $\Delta$(1232), yet with a sizable impact of the $N$(1440) and
non-resonant partial waves.
