We begin with the new shock wave, what authorities believe those boston bombers were planning next. Hoping to head to times square in new york. A live reminder tonight of one of the busiest tourists... See More
We begin with the new shock wave, what authorities believe those boston bombers were planning next. Hoping to head to times square in new york. A live reminder tonight of one of the busiest tourists destinations in the world. Nearly half a million people passing through the heart of new york every day investigators say one choice, one move might have derailed their own plan. That carjacked mercedes had little fuel in the tank. Whether they went to the gas station, the whole plan began to unravel. Brian ross back with us here tonight. This was chilling today. Indeed, based on what the mayor and the police commissioner said, new york just missed being attacked by the accused boston bombers who late last week decided they want to maim and kill even more. The decision to target times square was spur of the moment, that's what the new york mayor says the surviving brother that he and his brother had intended to drive to new york and designate additional explosives in times square. Reporter: But new york was spared, officials say, at the moment the two accused bombers had to stop for gas in the car they had hijacked in cambridge. And the younger brother, 19-year-old dzhokhar tsarnaev went inside for snacks. The driver used the opportunity to escape and call the police that led to the shootout in watertown. Reporter: That shootout, captured in these still photos involved a violent gunfight, and authorities said the two had at least six bombs, including another pressure cooker device seen here. Just some of what might have been used in times square. We don't know if we would have been able to stop the terrorists if they had arrived here from boston. We are just thankful that we didn't have to find out that answer. Reporter: New york officials said 19-year-old dzhokhar tsarnaev told the fbi he and his brother would go to norge just to party as he did twice last year with some of his college friends, leading to this photo being posted on an online russian social network site. But in a second hospital interview sund night, dzhokhar told a different story, officials said, revealing the times square plot and speaking in his own voice. He's more lucid, we're told, in the second interview and was more expansive, giving more detail. Reporter: But despite all that, the extensive and graphic images, the mother of the two brothers insists her two sons are innocent and blames america for failing her family. I thought america was gonna like protect us, our kids. It's gonna be safe for any reason. But it happened. America took my kids away from me. Only america. The mother says she never wants to come to america again, but the father who is there at her side, said he plans to travel to boston this weekend to claim the body of one son and do what he can to help the other. Even after they saw the damage they caused in boston, they wanted to do more in new york. They had other bombs, they planned to use them.
This transcript has been automatically generated and may not be 100% accurate.