0 folks from the cdc to test the air yault and ensure it is safe. >> our coverage will continue enin hours as well.day and "the lead" with jake tapper starts right now. we're one hour away from a scheduled fbi press conference with the latest on the investigation here in boston. i'm jake tapper and this is "the lead." words of solace for the victims, survivors, first responders. president obama joined by the first lady con soelg the city of boston in its darkest hour. in texas entire blocks leveled, part of a small town reduced to smoldering rubble and a devastating chemical explosion. as many as 15 dead, more than 160 hurt, several still missing, and no one is sure exactly what caused it. finding comfort in our national pastime. boston's beloved red sox wrapping up a stint on the road tonight and getting ready to return for their first home game since the attack. the intense sports rivalry between boston and other cities giving way to a spirit of solidarity. good afternoon. we're coming to you live from boston where president obama and the first lady have been visiting victims of the terrorist attack here. earlier they attended an interfaith service called "heal our city" at the cathedral of the holy cross one of the city's revered churches. the president offered prayer and condolences to the people who are still so shaken by the terrorist attacks at the boston marathon on monday. in a moving speech the president used the marathon as a metaphor for struggle, endurance, and ultimately, triumph over evil. comfort for a grieving city. >> like you, michelle and i have walked these streets. like you, we know these neighborhoods. and like you, in this moment of grief, we join you in saying, boston, you're my home. >> reporter: president obama delivering soaring ora tory with the first lady looking on from the first row attempting to calm nerves after what will be remembered as one of the worst moments of his presidency. part eulogy, part sermon, part rallying cry. >> if they sought to intimidate us, terrorize us, shake us from the values that make us who we are as americans, well, it should be pretty clear by now that they picked the wrong city to do it. not here in boston. >> the crowd began lining up at the cathedral of the holy cross a mile away from the bombing site hours before the service stretching for blocks beyond the church. many more than could possibly fit inside the 2,000 capacity building. those who found a seat listened as the president memorialized the three people killed in the terrorist attack, 29-year-old krystle campbell, 23-year-old chinese graduate student lindsay liu. the president became especially choked up when talking about 8-year-old martin richard. >> forever expressing a wish he made on a blue poster board. no more hurting people. peace. >> reporter: the president as consoler-in-chief, a role he has found himself in all too often. after tucson, after aurora, after hurricane sandy, more recently after newtown. as with those other terrible events now is the time for coming together. the service uniting religious leaders and people of all different faiths in one common prayer. >> to repair our broken world. we cannot do it as a collection of individuals. we can only do it together. >> reporter: as we mentioned before, immediately following the service, both the president and first lady michelle obama stopped at hospitals to visit with the wounded and their families. for many, the key to healing from the attack will come only after justice is served. in less than an hour we expect a briefing from the fbi and hopefully new details on whoever did this. agencies were trying to track down two men who were near the finish line using images that haven't been released to the public. a source who receives regular intelligence briefings on the investigation now tells cnn that those men are no longer of high interest. i'm joined now by cnn national correspondent deborah furyk. i guess we know why the investigators never released the images and now seems those individuals aren't of interest. >> they've been lowered down on the list. one thing that is very interesting is the way the pictures were disseminated. these were sort of given to members of the intelligence community and it was almost as if they went viral almost instantly. people were getting the photographs from sources they never would have gotten them from before. that surprised them. why were the pictures being sort of handed out, given this way? once it went viral it was hard to contain. cnn reached out to friends of one of the young men. they were of particular interest to law enforcement because of where they were standing. they arrived early and stayed throughout the course of the race. they were carrying backpacks. another had a duffle bag. it just didn't look right. it was the bulges on the backpack. investigators were looking at frame by frame to see what doesn't look right. these two men sort of fit that definition, that description. so absent context they basically had a look at the normal and said there is something abnormal about this. anyway they ultimately ruled them out. investigators have a lot of pictures they're analyzing right now. there are other people that are on the radar. now we've got to find them and they've got to either rule them out or they've got to raise them in terms of priority on the list. they're looking at surveillance. we are told they're looking at surveillance cameras that were along the route up to a week before and two weeks before so they can see who was traveling, who was looking for locations, possibly scouting those locations. this is going to be an intensive investigation. >> we know from looking at the photos ourselves there is no shortage of individuals there with black backpacks. what do you expect at this 5:00 p.m. press conference? >> it's very, very interesting. we got a memo from headquarters saying a 5:00 press conference but in bonneston everyone kept saying tentatively. they don't want to get burned, seem like they're going to have a press conference and then pull back and people read into it. we don't know. they may say we don't have anything. here is an update. i think the investigators want to keep people in the loop and keep them organized but at the same time they just may not have a lot that they can tell because all of this is part of the criminal investigation. all of it will be brought forth for a trial in the event there is a trial. >> thank you so much. we'll come back to you soon. president obama said for millions of us what happened on monday in boston is personal. and you can bet it was personal for my next guest, the president and ceo of the boston red sox, larry lukino thank you so much for joining us. he attended the interfaith service where the president spoke. your thoughts on what the president had to say today. >> the president was pitch perfect. he was presidential, inspiring. he was -- he showed a familiarity with what was happening here locally. he inspired everyone i think to behave as well as we can in the days going forward with as much inspiration as possible from the good works done by the people in boston. >> now, i hate to bring up a sore subject but tomorrow night you have a game. >> we do. >> this will be the first game since -- here in boston since the attack. are you taking extra precautions? what are your concerns? >> we are. first of all we think it's important, baseball can play a role as the bruins and hockey did last night in helping the community heal, helping it come together, expressing some of the sentiments we all share and feel. the mayor did that today so well as he demonstrated kind of resilience of his own as he spoke of boston's resilience. tomorrow night is an opportunity for boston to come together and for us to pay a low key tribute to the people who behaved so bravely and to show support for the victims. >> what, specifically, do you have in mind for tomorrow? >> well, it will basically be a low key, not pageantry at all but a low key tribute of appreciation for the way people behaved, first responders, volunteers, doctors, nurses, blood donors, all of those folks, and an effort to show to the world some of the resilience that the mayor talks so eloquently about today that bostonians will come together and this is the wrong city to -- >> to mess with. i assume some added security? >> yes. we certainly -- public safety has always been a major concern of ours, but in the last several days we've taken steps to increase it. we asked our fans to come to the game a little bit earlier. just because there will be extra precautions and extra personnel at the ballpark for tomorrow. but that's the highest priority for us always. >> now, i have to confess, i'm a phillies fan. >> it's okay. it's the other league. >> i hate the red sox and the yankees though we're all red sox fans today. >> thank you. >> but you've referred to the yankees in the past as the evil empire, which i completely agree. it must have meant something to see what the yankees did in homage to this team, which the two of you have such a celebrated rivalry. >> yes. it meant a great deal to us. the banner that they hung alongside yankee stadium saying united we stand with the red sox logo and the yankee logo and singing "sweet caroline" in yankee stadium was almost surreal. but a lot of other teams in baseball reached out in the same way and tried to express, send a tribute or their solidarity to us. philadelphia had a sign that said from one tough city to another. >> right. >> there was sweet caroline sung in several ballparks around the country. it is really important and it may not seem like much of a gesture to those folks but to us here realizing they care enough about us in boston it meant a great deal. i have tremendously fond feelings for my colleagues in baseball and particularly for the yankees reaching out as they did. >> thank you so much. i wish you limited success but continued success for you and happiness for the city of boston. thank you so much, sir. a nation already on edge from terror bombings and poison letters literally shaken again in less than a half hour we expect a press conference updating us on the enormous destruction in a small, west texas town. an explosion few have seen outside a war zone happened last night at a fertilizer plant in the town of west texas. the blast was so strong it registered as an earthquake and was felt 50 miles awachlt it flattened homes in a five-block area. witnesses compared it to what they saw in the early nights of the iraq war or perhaps even oklahoma city. police say between 5 and 15 people are dead. the number is almost sure to rise with more than 160 people suffering injuries. with the closest major hospital to the town of fewer than 3,000 people about 25 miles away. as we've seen so many times in these disasters, people ran into the danger zone as fast as they were running away. >> last night was truly a nightmare scenario for that community. but as i said earlier, we're blessed in this state to have the best emergency management team in the country and they certainly were at their best last night along with the citizens. >> chief medical correspondent for cnn dr. sanjay gupta is live in west texas. sanjay, thanks so much and good to see you. the national guard is monitoring the air quality around the blast area. what could happen to people who breathe in this chemical and hydrous ammonia? >> this is a very interesting, potentially dangerous chemical, a nitrogen fertilizer, jake. let me just tell you it's stored at high pressure and that is relevant because if it comes out of a tank, it can -- it's lighter than air, typically. in conditions like this, though, it can stay closer to the ground and cause what's known as an ammonia fog. if it touches your skin it immediately dehydrates your skin to the point where you can suffer burns. you heard probably, jake, the initial rescue efforts people had to wear respirators. if you breathe this in it can be quite damaging to your upper airway and lungs. that was the big concern obviously for the people in the area but also the first responders. i will tell you, jake, the state epa has been conducting air quality exams pretty regularly and so far the news seems to be good with regard to that. either because of the winds, the conditions overall, that air quality does not seem to be an issue. you do have the concerns still as you pointed out about the initial explosion, the primary blast, the secondary blast, some of the same things we've been talking about in boston but also the fire and these flattened buildings that you mentioned. by the way, if you're here, you'll know a four to five block radius you just described is the town of west texas. small town about 2800 people. but the impact of this felt much further than just the town -- the boundaries itself, jake. >> how do you treat exposure to this gas? >> typically what you -- in a situation where you have a lot of this around the safety protocols are to have lots of fluid and water around as well because if somebody gets it on their skin you have to start flushing it immediately. because it is anhydrous which means without water, you sort of have to do the opposite. dehydrating the skin to the point of burns so you have to give water. people who ingest or inhale it often end up in hospitals and have to be treated in a way that is known as symptomatically meaning a treatment for the symptoms. if they're having difficulty breathing they may need breathing machines, often a lot of fluids replaced. there is no particular antidote for this sort of thing. you have to flush it either off the body or out of the inside of the body as quickly as possible. when you talk about these people that are in the hospital, hill crest hospital, that may be what some of them are being treated for. the majority, again, for these blast injuries, i should just point out, because you're there in boston there is one hospital here, 25 miles away. 237-bed hospital to try and treat most of these injuries. it is a very good trauma hospital. but where you are and where i was yesterday nine hospitals to take care of the injured. it is a very different situation in terms of resources here as well, jake. >> exactly. dr. sanjay gupta in west texas, thank you so much. when we come back, can you find the boston bombing suspect or suspects in these photographs? 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