A woman in a burning Dallas apartment building dropped her baby from the third-floor window. Other residents leaped onto a mattress to escape the flames. Dallas Fire-Rescue spokesman Jason Evans said several residents and bystanders, assisted by police officers, went door-to-door to alert others on the fire Wednesday morning. Officials said three people, including a firefighter, suffered minor injuries. Investigations are underway to determine how the fire started and destroyed about two dozen units.