On the Singularities of Reissner-Nordstr\"{o}m Space-Time
  It is shown that if two Reissner-Nordstr\"{o}m space-times, both with the same mass m and charge e, glued together in the singularities, then the light ray in black hole of the first space-time can go continuously through the singularity into black hole of the second. The behavior of tidal forces near the Reissner-Nordstr\"{o}m space-time singularity is examined by considering what happens between two particles falling freely towards the singularity. 
M. Abdel-Megied and Ragab M. Gad