he grabs krish while other passengers pull meera to safety. >> my son was taken out right away by thatutely incredible. i have no words for it. >> with no time to spare, all three are back on the platform. but it's the beginning of a long night. >> immediately we were taken to mass general hospital. >> meera escapes with only a swollen knee, but doctors monitor krish for head injury. >> he kept crying for five, six hours. that's how they found out he's not in any type of danger. he doesn't have any internal head injury or anything like that. >> in the heat of the moment, meera doesn't get a chance to thank their rescuer. news reports identify him only by his first name chris. >> i would again and again tell him thank you so much. >> meera says she would have kept the incident quiet, but the story quickly circulates around the globe. >> i didn't want to tell anybody for at least a couple months. but i couldn't keep it for a couple days. >> a terrifying video from boston when a woman carrying her 4-year-old child walked straight off the platform. >> my family members back home, they saw