Nightly News | April 15, 2013
>> katy tur who made her way up there. as i understand it there are 15 blocks that are virtually frozen. people have been told to shelterer in place and once they go out, avoid crowds which is tricky on this day which is a holiday every year.
>> reporter: it's pretty tricky in this area, brian . this is the back bay of boston . it is a popular area. it is a busy area on a normal day. it is chaotic here during the marathon in a good way. the bars are open. people are out. right now there are people here. they want to see what's going on. i guess they are trying not to congregate. for the most part it's quiet for this area. after the explosion there were streams of people walking the streets. the subways were shut down and because of that, people had to walk for miles in some cases to their destination. in fact, we are two blocks from the finish line . two blocks from where the explosions happened. we saw a woman right over here, witnesses saw her stumbling to this block with shrapnel wounds. nbc has confirmed shrapnel was part of the explosion. that's why there were lower limb injuries. people reported seeing tourniquets applied on the raceway. back bay is normally a busy area. there are a number of roadblocks. there was a ground stop at logan airport . we had to circle over providence for quite a while before they allowed us to land. as you would imagine, a very heavy police presence here. the national guard is here and people are on alert. they want to know what's going on. the police commissioner asked everybody to stay inside, everybody to go home if they can. from what you can tell although there are people out here, most of them have heeded the order oh, at least around here. brian ?
>> we can see looking at tape of the finish line the digital seems to say this was the 4:09, four hour, nine minute finishing mark. if you are crossing the finish line at that point in this race you have done very well. to finish at all you have done very well. but people thought, and you can't blame them, that this was some kind of cannon, a planned thing. i had one eyewitness describe it in terms of world trade . that once the second building was hit that day we knew it was something different. well once the secondary explosion went off, they knew it was not an accident of the construction of the city like a gas main.
>> reporter: certainly when you're at a marathon, especially in boston where they haven't had issues like they have had in new york, nobody was expecting something like this to happen. initially nobody thought -- they weren't sure if it was even an accident, a gas main break. people didn't know what was going on. when the second explosion happened 15 seconds later people started to believe there was something fishy, something bad. that's when people started to get scared, run away. a bit of a chaotic scene out here. brian ?
>> kay tur on the streets of boston . we don't know when people will be allowed back in.