Of silence being observed by the people here in brussels, belgium. That is a place called the place de la bourse. It is about a mile and a half from where im standing. Moment of silence, part of the kind of trying to come to terms with what has gone on here in the last 24 hours. As i mentioned, im here in brussels. Savannah is back in new york city. Savannah, weve got an awful lot going on right now. Breaking news on the investigation into these attacks. We know the names of the suspects in the airport bombings. Two brothers. Khalid and ibrahim bakraoui, identified as the suicide bombers. The third man, the man in white with the black hat, hes been identified as Najim Laachraoui, already wanted in connection with the paris attacks. There are some reports he has been arrested. I want to say that nbc news has confirm those reports. Now, raids are being carried out all across brussels. One of them led to the discovery of what investigators are calling a bomb making factory. The attacks are inspiring a show of solidarity around the world. Iconic landmarks across europe and the u. S. Have been lit in belgiums national colors. Black, yellow and red. There is a lot to get to this morning. We want to start with nbcs keir simmons, joining me right now here in brussels. What can you tell us . Conflicting report, but a key suspect has been arrested, its not going to help the tension here. There has been fear here in the city and across europe ever since the paris attacks. What yesterday did was shatter peoples confidence. A sense that europe is under attack. Reporter in europes rainsoaked capital this morning, soldiers questioning outside the subway. Today, just going to work is an act of defiance. Frightening. Yes, yes, absolutely. But youre still determined to get to work . Yes, i have to. We cannot give into fear. Its going to we have to show that we can go on. Reporter on the same streets, an urgent man hunt to find killers who struck in the name of isis. The two suspects suicide bombers at the airport, seen in security video, identified overnight as brothers khalid and ibrahim bakraoui, each wearing inin ini on one hand, investigators trying to figure out why. Transporting their suitcases to the airport in a taxi. The man with them identified as Najim Laachraoui, now wanted by police. Already many questions. How the men easily entered the airport, smoke, fear. Maelbeek metro an hour later . Subway doors blown out, passengers escaping along the traps and echoing along the tunnels, screams. [ sirens ]. Reporter there are some answers. In schaerbeek, a makeshift bomb found. Ingredients for explosives and an isis flag. Nbc news learning authorities have found additional suitcase bombs. There is mounting criticism of europes intelligence agency. For failing to prevent this attack four months after the paris massacre. Overnight, we crossed european borders with ease. Weve just crossed the border into belgium. No checks, no sign of police. If the suspects wants to escape to another part of europe, they may just drive. Reporter among the injured, missionaries from utah. And this couple, mi families say. This man was dropped off at the airport by a friend when the bombs went off. I saw this bright light, followed by a huge explosion. I was just stunned. Reporter this morning, he is wearing the same clothes. He left his bags behind when he fled in terror. The french Prime Minister this morning saying europe has closed its eyes to the rise of extremist ideas. They want to destroy our way of life. He says this has the potential to have a profound effect on the way folks in u. S. View europe. That may have already happened, keir. Thank you very much. Good to see you. As the hunt for more potential suspects intensifies and continues, what are we learning about the attackers who have been identified . And their suspected ties to isis . Bill neely is also in belgium. This he has that part of the story. Go there are reports of an arrest close to here. Belgian media are quoting sources as saying it is the main surviving suspect from yesterdays attacks. But nbc news cannot confirm that. What we know here yesterday, in the suburb of schaerbeek, police raided an parapartment over the and found explosive material and an isis flag, all of it part of an isis terror cell much bigger than police ever understood. Reporter brussels, the capital of europe, woke this morning to a man hunt after a massacre. This is the prime target, Najim Laachraoui, a 24yearold belgian who has already eluded police for months, escaping after the attacks in paris. He and the two bakraoui brothers, khalid and ibrahim, are seen here in the airport. They are wheeling their suitcases themselv blowing themselves up. They both had criminal records, one for shooting at police. Laachraoui, for some reason, didnt explode his bomb and escaped. The death toll here could have been higher. Police began gathering bags of debris from the attacks, searching for clues on how the bombs were made. They believe there may be a single bomb maker behind the attacks in both brussels and paris. Very alarming to find out how many people involved in this, and their ability to get ahold of or to make high explosives and to set them off in such a spectacular fashion. Reporter late yesterday, Police Helicopters and snipers honed in on a house in brussels where it was thought some of the men were based. They searched it, led to the address by a cabdriver, who had taken three men with heavy suitcases to the airport. There have been other raids, other arrests, but so far, no e accomplice. As Police Search for suspects, belgian troops are on the street, protecting key locations. Metro stations are open, but people are being searched as they go in. This is a nervous city. Reporter last week, Police Arrested salah abdeslam, who took part in the paris massacres, at a brussels apartment rented by one of yesterdays bombings. It is clear theyre all part of the same isis cell. Police suspect his arrest triggered their plans to attack brussels. Police were braced for some sort of attack, but not on this scale. This was clearly a massive intelligence failure. But if reports this morning are true, that someone has been arrested, this could be a break through in cracking open europes deadliest isis terror cell. Matt . Bill, it would be welcome news to a lot of people around here. Bill neely, thank you very much. Now a chilling account of the attack at the airport in american jeff hoffman, a consultant for nato, lives here and was dropping off his girlfriend when the bombs went off. We talked to jeff yesterday. Happy to have you with us. How are you . Doing okay. A little shaken still . Yeah. I dont think itll go away any time soon. We talked yesterday. You were eloquent in describing what you went through, but i got the sense you were in shock a little bit yesterday. Have you come to terms with other emotions in the last 18 hours . You know, its funny, i dont think there has been too much to come to terms with. I think i woke up this morning, and it was okay, that happened. We were uninjured. We got out. Consequently, personally, i move on from that. All the what ifs and the other questions you can ask yourself, i really dont. Your boyfriend described dropping you off at that airport, standing inside the departures terminal when the first blast went off. What do you remember about it . I think old normal, i guess, lady handed me my baggage tickets. I turned to look at him, and he smiled his little grin. Then i remember it was a whirlwind. It was almost like a tornado going off behind him. Stuff flying everywhere. That hit me. I felt it before i heard it. I still didnt know what was going on. I didnt understand what was going on until he was coming towards me. I thought, oh, an accident happened. I dont know. It was pretty clear after seeing the terror on his face, that that wasnt an accident. I have to say that watching the video is hard enough, but there have been portions of the video that weve listened to the audio of. Hearing the screaming, hearing one young child calling, mommy, mommy, mommy, were you aware of the sounds going on around you, as well . For me, after the first explosion, which i turned to, there was a lot of screaming. I dont think i really was able to filter through and hear specific sounds. The unsettling thing for me personally explosion, was dead silence. We talked about that yesterday. That was the most unnerving part. In an incident like that, you almost expect that you would hear Police Activity, people shouting. It was quite literally, if i can kind of compare it to anything, it was almost as if everyone was gone in a moment. As in, we were the people around us, i was crouched beside the counter and she was behind the counter, it was as if we were the only people left in the airport and it left you feeling exposed in a way. I dont want to bring up a difficult subject, as if this all isnt difficult, but you were on your way home. Im assuming youre still now trying to get home. Yeah. That would require going back to the airport and boarding a flight. How do you feel about that . He says everything is going to be okay, so i want to believe him. I dont really ever want to set foot back there again, but i need to get home. Im going to do what i have to do. Its g you have to be brave, i guess, be strong. I mean, im lucky enough to be able to go home and get to see my family. A lot of people arent that lucky. I try to keep telling myself that. Dont think youre going back to a terrible place. Its your catalyst to get home. Good way to look at it. Great to meet you. Nice to meet you. Good to talk to you again. Thank you so much. Lets go back to you, savannah. Matt, thank you so much. As you would expect at home, security is being stepped up at airports, train and subway stations across the country in response to what we saw happen in brussels yesterday. Pete williams is at Union Station in washington, d. C. This morning. The train station there. Pete, good morning. Savannah, good morning to you. Rail commuters across the country can expect to see more security on the ride to work this morning. Airline passengers will see it, too. It is a precaution. Officials say theres no intelligence warning of a similar attack here. Reporter on commuter trains and Subway Police are out in a highly visible show of force. Beefed up security, too, in miami, chicago, and atlanta, with heavy armed foot patrols. More security, too, at many of the nations airports, especially in the outer lub, where the Airline Ticket counters are. Nationwide, specially trained units and bombsniffing dogs. Plain clothes officers, too, and search of bags. We want communities to feel confident that were here, were able to respond. We have enormous capability if we need it tactically. Reporter amtrak is adding police and randomly screening luggage as passengers board the trains. Its an aggressive presence in new york city, with 50 officers surging into times square. The mayor made a point of riding subway to demonstrate the safety. Expect to see extraordinary nypd presence out over the coming days, as a sign of our readiness to protect people at all times. Protecting mass transit there is a big chore. We employ a lot of technology, and we pay very close attention and learn from attacks that have gone on around the world. We deploy and train accordingly. Reporter most commuters say theyre taking the extra security in stride. Ill be cautious and aware of my surroundings, but i also know i have a choice not to let it hold me back. Reporter train and subway riders and airport passengers will see more security for at least the next several days. And fbi agents are stepping up surveillance of terror suspects, looking for signs of copycat attacks at home. So far, Officials Say no sign of that. Savannah . Pete williams, thank you. General Michael Haden served as director of the cia. Good morning. Good morning. These attacks show we need to up our game, your words, and be better prepared. What does that mean in practice . Is this cou we are vulnerable, but not nearly as vulnerable as our european friends. There are a lot of things that are different. We have very good intelligence and security services. Its not a universal condition in europe. Were distant from the battlefields and, frankly, savannah, we are a different society. We assimilate immigrants better than our european friends do. The level of threat here is not zero, but its not nearly what it was yesterday in europe or, frankly, is today in europe. You mentioned the failures of intelligence. We now know that authorities are looking for the socalled man in white, a person by the name of Najim Laachraoui who, in fact, was being sought for the paris attacks. Does that ind koicate theres b a breakdown in terms of Law Enforcement overseas . Obviously, there was a failure because the attack took place. It may be a question of limited resources, as opposed to anything else right now. Many of the services in europe are small. The belgian particularly small. Then, savannah, i have to add, theres been this grand debate over the last several years about the proper role of intelligence collection and individual privacy. The europeans have come down very strongly on the side of individual privacy, criticizing the United States. There was an interesting column in this mornings post, where it said the europeans are turning to the american intelligence for intelligence products. Even though they object to american intelligence collection. We need to have that conversation over again with our european friends and, frankly, i think, make it a little more factbased than the conversation we had over the last 12 to 24 months. Very quickly, this all has taken place in the context of a president ial election here. You see proposals, particularly from donald trump, saying, lets close the borders temporarily to all muslims. You have ted cruz coming out saying, maybe there should be patrols and neighborhoods. They say that Political Correctness, their words, made us less safe. Do you agree . I think we need to have an adult conversation about the role of islam and the civil war within islam. Savannah, the main point here is in the United States, we may have radicalized individuals. We do not have radicalized communities. We have it within our ability to create radicalized communities and some of the rhetoric in the president ial campaign trends us toward that great, great problem. General michael hayden, good to spend a few minutes with you. Thank you. Thank you. These attacks are reignited debate in the president ial race over the best ways to protect our country. Voters in three states were heading to the polls on tuesday, and the results are in. It was a split decision on the republican side. Donald trump upon big in arizona. He stopped ted cruz by more than 20 points. Cruz took it in utah, grabbing all 40 of that states delegates a heres the overall count this morning. Trump with 744 delegates. 468 for cruz. John kasich behind. On the democratic side, Hillary Clinton took arizona. Bernie sanders won the two other states up for grabs, utah and idaho. Lets look at the democrat delegates. Clinton leads, 1,637 to Bernie Sanders 928. As we mentioned, all of the candidates have had a lot to say about the attacks in brussels. National security and how to best deal with the terror threat. Nbc National CorrespondentPeter Alexander is covering that angle of the story. Good morning to you. Good morning. First, a surprise announcement today. Jeb bush is endorsing ted cruz, in his words, to overcome the divisiveness of donald trump. This follows a day that focused on policy and turn sboed into a personal feud. Reporter terror aprod folbr followed by tough talk at home. Were coming after you. Reporter trump says police, in his words, patrol and secure muslim neighborhoods here in the u. S. Before they becomrade calizcal i become radicalized. We need to stop isolated communities from festering jihadism. Reporter the head of the nypd slamming cruzs comments. I take great offense at his characterization of that whole population. Reporter donald trump crediting cruz for a good idea. John kasich, more critical, warning against alienating muslim americans, needed to combat terrorism. Just because you happen to be a muslim doesnt mean that you are a radicalized person that wants to destroy somebody in the west. Reporter the competing responses underscoring stark contrasts between the candidates. I would close up our borders to people until we figure out whats going on. How high does the wall have to be to keep the internet out . You know, thats not the world we live in any paris bomber and other terror suspects, trump embraced torture tactics. Waterboarding and more, he said. If they would have put him through the grill ten minutes after the capture, he probably would have ratted them out and maybe stopped this horrible terror attack. Reporter a new ad from an antitrump group that targeted mormon voters is turning heads. With, meet melania trump, your next first lady, to r yor you c support cruz on tuesday. Trump said, be careful or ill spill the beans on your ad. Cruz said if you attack heidi, youre more of a coward than i thought. Classless. The next faceoff is wisconsin, less than two weeks now. Peter alexander in washington, thank you very much. By the way, well be talking to republican candidate ted cruz. Well ask him about that a little later this morning. Let turn to dylan, in for al coast. Very nice warmup. Temperatures approaching 70 degrees in the northeast. Through the upper midwest, were talking about a winter storm. We have a lot of snow expected through parts of denver, under a blizzard warning now and lasts through this evening. Into parts of minnesota into wisconsin also watching for severe storms in the midwest. Thats a look at the weather across the country. Your local forecast is coming up in 30 seconds. Good morning cs morning. Temperatures are in the 50s. Not producing any rain at all. Later today more sunshine. Highs soaring to the mid70s. Another day like today tomorrow. Morning showers on friday afternoon sun back with highs mid 60s. Into the easter weekend, saturday sunny. Chilly in the morning but afternoon highs mid60s. Upper 40s on sunday, thats your latest forecast. Matt . Dylan, thank you very much. Coming up, well remember the victims in brussels, as the tributes for them continue to pour in. But first on a wednesday morning, this is today on nbc. Just ahead, the troubling scenario in the wake of brussels. How do y