. >>> allyn weisselberger remains loyal to trump. the former president's niece predicts his kids could throw him under the bus. >> i think he would be surprised to learn that i don't believe my cousins would exert -- exercise that kind of loyalty because his relationship with them and their relationship with him is entirely transactional. so -- and conditional. >>> tensions rising within the republican party as liz cheney defies kevin mccarthy and joins the democrat-led investigation into the january 6th riot. the possible fallout and why she says she did it. >>> plus -- >> i have plenty of games left in me to compete in. and i have plenty of talent that backs me up because of everything i do comes to me naturally. >> an olympic dream cut short for r for a track sensation as she tests positive for marijuana. a debate over what some consider to be outdated and even racist policies. >>> good morning, it's saturday, july 3rd. i'm dara brown live from msnbc headquarters in new york. we have a team of reporters and analysts following the

allyn: or something.a is that i don't think all these different things that i have read, and we haven't been able to test anything yet, i don't think they were the necessary trigger. they may have been a contributing factor but not a trigger. that is what the big challenge will be, to find the trigger, and look at the various things that have been reported and say, if this was arrested like this, or if this concrete was soft or whatever, how might it have affected it? william: miami is under lots of stress, from sealevel rise and flooding. we know the area was built on very porous limestone. and then there is this tragedy. must be hearing from building owners up and down that region saying, do we need to worry? what are they saying? allyn: yes, we are hearing from lots of those people. what they really want is some assurance from somebody that they feel comfortable with that they don't have any problems, that they're building will not fall down around them like the one in surfside. we are talking to them.

so it is just going to take a lng time. >> brangham: allyn kilsheimer, thank you so much for your time thank you, sir. >> woodruff: there is a long history of foreign troops leaving afghanistan after long and bloody fights. now, the u.s. and its allies have almost completely withdrawn. nick schifrin explores how these decades of war look to veterans who served there. >> schifrin: the united states will soon complete the withdrawal of almost all military forces in afghanistan. the war in afghanistan has been america's longest. the u.s. invaded in october 2001, nearly 20 years ago. we thought we'd mark the withdrawal by talking with three veterans of the war about their experiences and what was accomplished. major megan pickle evans has been in the military since 2004. in 2013 she led an all female cultural support team who would speak to mostly afghan women in villages. she is still in the army. former specialist izia james was in army connaissance, surveillance and acquisition team outside of kandahar city in 2010 to 2011. he also served two tours in iraq before he went to afghanistan.

cbs' allyn kilsheimer rertsom ty officers s january akerecr s comttee to probe the attack. >> the next step for us has always been to seek and to find the truth. >> reporter: a surprise pick to join democrats on the panel: republican liz cheney, who voted to impeach former president trump and was removed from party leadership earlier this year. >> i was shocked that she would accept something from speaker pelosi. it would seem to me, since i didn't hear from her, maybe she's closer to her than us. i don't know. >> reporter: minority leader kevin mccarthy denied threatening fellow republicans that he would pull their committee assignments if they served on the panel. cheney said she wasn't concerned. >> i have not been, but, again, my oath, my duty, all of our oaths and our duty is to the constitution, and that will always be above politics. >> reporter: leader mccarthy would not say when he plans to name his picks for the panel, but speaker pelosi indicated the committee is ready to move forward with or without those republicans. norah. >> o'donnell: nicole killian, thanks so much. and

. >> reporter: allyn kilshimer is a structural engineer who consulted on disasters like the fiu bridgee and the 9/11 attack on the pentagon. he's been hired to investigate the champlain towers collapse and the work has been nonstop, nearly 13 days. >> everything's part of our investigation. we're not going to discount anything. >> reporter: over at the site of the champlain towers collapse, crews are working round the clock. but the painstaking work in the rubble is slow going. especially as hurricane elsa churns in the gulf. miami will miss the worst of the storm, but rain and wind make rescue and recovery even harder. >> these teams continue through extremely adverse and challenging conditions. through the rain and through the wind, they have continued searching. >> reporter: surfside's mayor says concern extends beyond the collapse. officials now worry about champlain tower's sister complex to the north, built by the same developer around the same time. the president of that condo association telling me last week, the building is completely fine. >> we have some concerns about not j

. >> reporter: but investigators like allyn kilsheimer will also review photographs, including some that bring into question t the layout of steel reinforcements in the building's concrete supports. >> it doesn't mean there weren't the right number there. they may not have been arranged properly. >> reporter: we're also learning more about the lives lost, like 58-year-old david epstein, was recovered two days after his wife bonnie. their son jonathan epstein posted on facebook, my parents there were concerns tropical storm elsa could topple what remained of the building before crews were able to demolish it. they brought it down just in time. the outer bands of elsa are already impacting surfside, but officials say the search will only stop for lightning or winds above 30 miles an hour. major. >> garrett: manuel bojorquez, thank you. we turn to the covid pandemic and a startling rise in the and a startling rise in new cases of the delta variant, accounting for one in four cases nationwide, this as the pace of vaccinations has slowed to a crawl. more now from cbs' carter evans. >> reporte

. >>> allyn weisselberger remains loyal to trump.could throw him under the bus. >> i think he would be surprised to learn that i don't believe my

. >>> joining us now is allyn kilsheimer, founder of kce structural engineers. he hare hoard by the town of surfside to investigate -- he has been hired by the town of surfside to investigate the collapse. i want to know more on your thoughts on this planned demolition. what exactly is involved in this process. >> the gentleman who has been hired is one of the best. they place explosive charges at various elements in the building. they are timed so you can control which charge goes off, by doing that you can kinds of control how it is going to come down. the difference here is usually that's done with a building that's still standsing and you just want to take it down. this building has been compromised. the parts that are still remaining have been compromised. so it may or may not behave the way a normal building would behave as far as coming down as planned. >> we heard the mayor mention that term that many of us probably haven't heard before, energetic felling. how safe is that? should residents in nearby apartments be concerned at all? >> generally speaking,

. >> allyn kilsheimer, thank you for being here. i know it's been a busy couple of days.so much. >> thank you. >>> coming up, to booster or not to booster. we're going to talk to our covid expert about how you should navigate all these mixed messages and whether the u.s. has it wrong. >>> and later on the "cross connection" nikole hannah-jones and t.a., whether to join and whether they belong at 10:00 a.m. eastern. elong at 10:00 a.m. eastern ...me. my symptoms were keeping me from being there for her. so, i talked to my doctor and learned humira is the #1 prescribed biologic for people with crohn's disease. the majority of people on humira saw significant symptom relief in as little as 4 weeks. and many achieved remission that can last. humira can lower your ability to fight infections. serious and sometimes fatal infections, including tuberculosis, and cancers, including lymphoma, have happened, as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. tell your doctor if you've been to areas where certain fungal

. >> reporter: allyn kilsheimer said it won't be until they can account for as many people as possiblehat rubble. then after they demolish the rest of the tower here. then after he and other experts can physically get into the rubble and painstakingly examine it. all of it. only after all of that, he says, can we begin to find out the reason for the collapse. all of that could take months, kilsheimer says and he's asking all of us to be patient. brian todd, surfside, florida. >>> in the wake of the collapse, the safety of nearby kondos, calling for the immediate evacuation and closure of one building deemed unsafe. cnn's rosa flores has the details. >> reporter: the city of north miami beach asking all of the residents of the building you see behind me to evacuate. officials say that the building is structurally and electrically not safe. here's the backstory, this bidding was bit in 1972. it has more than 150 units. and according to the city, this building had not filed its 40-year recertification. well, after what happened in surfside and the collapse there, they say, that they've as

allyn kilsheimer, we appreciate you being here. >> you're welcome. >>> up next, we are following the breaking news out of haiti where the president was assassinated overnight. president jovenel moise and the first lady. president biden said we condemn this heinous act and moments ago he called it very worrisome. dan delose for the nbc news investigative unit. dan, good to see you. thank you for being here. what do we know about what happened here? >> we still don't know very much, but what is interesting is the interim prime minister issued a statement earlier and said that the attack was carried out in a coordinated way by highly trained individuals who were heavily armed. so the implication was this was not some lone actor or some amateur group and they might suggest they might be foreigners and they were speaking spanish and english in the french-speaking country there. we do know it is a country racked by political unrest and tremendous gang violence. >> all right. dan de luce, thank you very much for that update on a difficult story. i'm sure we'll keep following it. thank you.

. >> allyn kilsheimer is a structural engineer. >> no one really knows in detail exactly the condition of the remaining building is. we also have a storm coming. so we're looking at the storm and what it does to the building. >> could the storm knock the remaining parts of the building down. >> everything is possible. >> reporter: earlier thursday president biden and the first lady paid respects at a growing memorial after meeting with first respond esper. >> the whole nation mourns with the families seeing it every day on television. they're going through hell. >> reporter: moments earlier mr. biden privately met with survivors and victims' families for nearly three hours. >> reporter: the president came union and spoke a few things. i'm here for you. hang in there. >> including steve rosenthal who lived in the condo 20 years before it collapsed. >> we lost everything. when he was finished he literally went to every table, talked to every person and as long as you were talking he was listening. it was amazing. it really was. >> reporter: fema says it likely be weeks before the rest of