  We investigate the chemo-dynamical effects of multiple supernova explosions
in the central region of primordial galaxies using three-dimensional
hydrodynamical simulations of the inhomogenous interstellar medium down to
parsec-scales. We find that the final protogalactic structure and metal
distribution depend strongly on the number of SNe. Specifically, 1) 1000 SNe
after an instantaneous burst of star formation are sufficient to almost
completely blow away the gas in these systems, whereas 2) 100 SN explosions
trigger the collapse of the protogalactic cloud, leading to the formation of a
cold, dense clumpy disk (n > 300 cm^-3) with metallicity, Z = 4 10^-4 Z_sun.
These results imply that the metallicity of the ``second generation'' of stars
could be Z ~ 10^-4 Z_sun, and that the environment to form metal-free stars in
protogalaxies may be lost relatively quickly (< 10^7 yr) after the first burst
of Z=0 star formation. The recently discovered ultra-metal-poor star
(Christlieb et al. 2002) may represent surviving members of such
second-generation star formation.
