a woman and her baby weren't doing anything wrong. they were on a sidewalk down on the street but events beyond their control put their lives at risk and a security camera saw it all. cnn's mary snow has the story behind this frightening video. this is just unbelievable to watch. >> it really is, jim. when you see this video and you know that both mother and baby were not seriously hurt it is nothing short of amazing. the teen mother heading to an exam at her high school suddenly found herself racing to save her daughter's life. it's terrifying to watch. a young mother and her baby walking on the sidewalk, then in a split second a car careens out of control and hits them both. 17-year-old alondra is grateful for what is, that she is now safe at home with her daughter pearla but it is the nightmare of what could have been that keeps playing over and over in her mind. she says when the car headed toward them, she tried