Transcript for Survivors of the Beirut explosion recount feeling the blast, its horrific aftermath
Reporter: In the midst of chaos and horror, a mother comforts her 4-year-old daughter with a lullaby. As their ambulance, packed with the wounded, navigates the streets of Beirut's Lebanon after a massive explosion tore through the city. I am thinking I should be stabilizing these patients. I should be working on them, but who's going to hold my daughter if I'm doing that. I'm trying to position myself in a way that prevents my dotter from seeing complete carnage. Reporter: The doctor, trained to work in combat Zones, finding herself in the middle of one at home. Now switching between pediatrician and parent. I'm telling my daughter, look at me, honey, just look at mama. I want you to look straight in my eyes, and we're going to think about our favorite place, the beach. If you feel any liquid on your legs, we're going to think about that like the beach. Obviously, I'm talking about blood coming out of her legs. Reporter: Outside the ambulance window, parts of Beirut in ruins. The blast killing 135, including one American, 5,000 injured and many still missing. The shockwaves leveling buildings, blowing out windows, felt over 100 miles away in Cyprus. Authorities believe the cause, over 2,500 tons of highly explosive ammonium nitrate stored for six years at a warehouse at Beirut port. This was the port before, and now today, a crater. Moments before the catastrophe, a city churned with the rhythms a priest blessing the altar, a bride posing for photos. Even a jet skier in the harbor. None could even imagine what would happen next. I have been through a bomb blast, but the intensity of it felt like nothing else I've ever experienced. Reporter: The first signs of trouble came around 6:00 P.M. Tuesday. White clouds billowing in the air. Smoke coming from a fire at this warehouse, followed by bursts of flames like firecrackers. Then a massive blast, a mushroom cloud blooming overhead. A pink chemical cloud taking its place. Summer hadid lives a mile from the blast site. I was in my apartment when I first felt the blast. I felt an immediate shake, and gloom, almost as if there was an earthquake and a bomb explode all at once. Reporter: Glass shattering all around her, her apartment is in ruins, so she fled the building, worried it might I was terrified. Seeing the blood on the staircase, seeing how injured my neighbors were was quite distressing, but we needed to get out of there. Reporter: Navi bullos was so disoriented he couldn't remember taking these photos. He hopped on his motorcycle to get a better view. I headed toward the port itself on the motorcycle, and I guess 15 minutes later is when the biggest one hit. The shock wave of the second larger blast must have hit then and threw me off my motorcycle. Reporter: Navi left shaken and injured, he believes his helmet saved his life. The visor bore the brunt. I felt these hands wrapping around my forehead. Reporter: Chaos on the streets and also in overwhelmed hospitals. An immense display of courage and solidarity, but it was also exactly like a war zone. There were people lying on the ground. It's literally a sea and maze of limbs that we're trying to get through, of people, and then looking over and realizing, even though you're worried about your kid, that thank god she's not the one next door that they're doing cpr on. We see everything from bodies completely disintegrated, shattered, to individuals, victims completely crushed by buildings, by vehicles. Victims burned by the heat of the explosion. Reporter: The health care system already battered by a six-month battle with covid-19. The blast coming on the first day after the city emerged from lockdown over the virus. Imagine in the middle of this you have a sudden event, like this explosion, that brings in two or three hours 4,000 victims to the nearest hospitals. They're already starving for health care supplies. The health care system is over extended, underfunded, and so are the people. Reporter: The pandemic and economic collapse hitting as the country was already facing a staggering financial crisis. So, in the past few months, I've seen basic groceries go to for what used to be $100 a week to $450 a week for two, for a family of three. So hunger is real. The threat of hunger is real. That just does not bode well for this country. Reporter: And this is what's left of the grain supply for the entire country. This has really exacerbated just multiplied the suffering in Lebanon. You hear people say here that we're cursed. You know, as Lebanese people, we're cursed. Reporter: Today the city recovers the dead and searches for the missing, looking for any survivors in the rubble. Reports of up to 300,000 homeless from the blast. The death toll expected to rise. The explosions now under investigation. The massive amount of ammonium nitrate had been confiscated from a freighter. According to reports attributed to Lebanese officials, there had been multiple warnings about the way this highly-dangerous material was being stored at the port. The main feeling here is sheer rage. The fact is, this explosion was a function of negligence, or at least people see it as such. The materials that were stored at the port have been there since 2015. This despite repeated requests to move them elsewhere, and yet those requests were completely ignored. Reporter: Lebanon's prime minister vowing justice, saying those responsible will pay the price. Lebanon's president announcing that the port officials have been put under house arrest until an investigation determines who's to blame. Some officials are pointing to gross negligence, but president trump insinuating something more sinister, seemingly without support. I've heard it both ways, too. I've heard accident, I've heard obviously it must have been some sort of explosives. Whether it was a bomb intended to be set off, it ended up being a bomb. Reporter: That despite his defense secretary saying otherwise. It's an accident, we have nothing more on that. We're willing to supply whatever we can to assist the people of Lebanon. Reporter: Aid now being offered from around the world, even from Israel, Lebanon's sworn enemy, offering humanitarian and medical assistance. Reporter: Iman and Seema were discharged from the hospital this morning, a mother now finding new words to comfort her dater. So many people say always what Mr. Rogers said, look for the helpers. That's certainly what you would tell a child. As you grow to be an adult, your job is going to change, from looking for helpers to becoming those people, so when there's a kid out there looking for a helper, he or she can look to you. Reporter: For "Nightline,"
This transcript has been automatically generated and may not be 100% accurate.