Fitchburg police say three children, each two years old, were sitting in the back seat of a stolen car when it slammed into a utility pole.  They weren’t injured.  Police had tried to conduct a traffic stop Thursday when the vehicle sped off.  Just a short distance later, it went out of control and hit the pole.  Witnesses told police where the two occupants of the vehicle had gone.  Officers were able to arrest two girls, 15 and 16 years of age.  The owner of the stolen vehicle had left it running and unlocked with the small children inside earlier in the day.