  We report on our study of asteroidal breakups, i.e. fragmentations of
targets, subsequent gravitational reaccumulation and formation of small
asteroid families. We focused on parent bodies with diameters $D_{\rm pb} = 10$
km. Simulations were performed with a smoothed-particle hydrodynamics (SPH)
code combined with an efficient N-body integrator. We assumed various
projectile sizes, impact velocities and impact angles (125 runs in total).
Resulting size-frequency distributions are significantly different from
scaled-down simulations with $D_{\rm pb} = 100$ km targets (Durda et al.,
2007). We derive new parametric relations describing fragment distributions,
suitable for Monte-Carlo collisional models. We also characterize velocity
fields and angular distributions of fragments, which can be used as initial
conditions for N-body simulations of small asteroid families. Finally, we
discuss a number of uncertainties related to SPH simulations.
