A Gojet Canadair CRJ-700 on behalf of Delta Airlines, registration N369CA performing flight G7-6202/DL-6202 from Saint Louis,MO to Minneapolis,MN (USA), was climbing out of Saint Louis' runway 12L when a bird impacted the windshield at about 4500 feet MSL causing the windshield to crack. The crew stopped the climb at about 5000 feet and returned to Saint Louis for a safe landing on runway 12R about 10 minutes after departure. The FAA reported the aircraft received unknown windshield damage as result of the bird strike.