On a sunny September morning in New York City 20 years ago, Phil Penman was getting ready to relax. It was the photographer's first day off in a long time after he had spent months working nonstop.
Joanne Capestro, meanwhile, was gearing up for another workday in the city. Even though she wasn't feeling her best that day, she had decided to go to work anyway. "The morning of Sept. 11, I woke up, I wasn't feeling well. I contemplated if I should go into the office or not. I said, 'You know what, let me go in,'" Capestro recounted on TODAY with Hoda & Jenna Friday.
Capestro, then 39, worked at the World Trade Center, on the 87th floor of the north tower. She was there on that fateful morning when American Airlines Flight 11 crashed into her office building at 8:46 a.m between floors 93 and 99.
"I was standing by my desk and boom, the plane hit," Capestro recalled.
Shortly afterward, Penman, then 24, received a phone call.
"Phone rings, I'm like, there's no way I'm working again today. It just went to voicemail," Penman told TODAY. He didn't pick up but he checked the message anyway. It was then that he knew a plane had hit one of the twin towers.
Penman scrapped his plans and rushed downtown. Once there, he started capturing what was unfolding.
"I'm looking up at the tower and I'm taking these pictures," Penman said. "Then all of a sudden, you hear this rumble and the building's coming down as I'm shooting."
At 9:03 a.m., United Airlines Flight 175 crashed into the World Trade Center's south tower.
"Our building shook. At that point, I really felt like someone jumped inside me and said 'Jo, Jo, you got to go,'" Capestro said of her decision to walk down 87 floors.
But the situation worsened once she got out of the north tower.
"I wasn't even outside 30 seconds and building tower two started to fall down on me," she said before she reunited with a co-worker, who had also managed to leave. "My girlfriend yells, 'Joey, Joey,' and I turned around and I saw her and I was like, 'Oh my God, what are we going to do now?'"
Penman was nearby and captured Capestro and her co-worker, Dominique Davis, as they escaped the World Trade Center.
"All of a sudden, you just start seeing like, the emergence of people kind of walking towards you," Penman said.
The photo Penman shot of Capestro and Davis was one of many he captured on that fateful day. Years later, Penman's photos were shown at the National September 11 Memorial & Museum in a 2015 exhibit. It was the museum's curator who recognized Capestro and connected her with Penman.
A close friendship blossomed after their first meeting. Capestro even credits the photographer for helping her heal in the traumatic aftermath of 9/11.
"I really felt so different from that moment on and it took me many years to heal," Capestro said. "Post-traumatic stress disorder is not easy. Living with survivor's guilt was not easy. But I have to say when I turned the corner, I owe a lot of it to Phil Penman."
For Capestro, Penman's photo has meant a lot. "I tell him all the time, 'I love you, Phil, you know, you gave me my life back.' Just in a picture alone.'
"Nobody could understand that because they weren't there. But when they see that photo, they go, 'Well, now I know what she went through.' The picture tells us a thousand words," Capestro shared.
"For me, looking over the images over the last 20 years, it's kind of helped me deal with it more," Penman reflected. "You start reevaluating everything in life, what's important to you."
Capestro added, "I love the fact that I could call somebody up that went through what I went through, and he understands, and he's always there for me. Phil is someone I'll be friends with for the rest of my life."
Since they reconnected, Capestro and Penman have kept in touch, talking on the phone and meeting up often.
"After many years, I decided, 'I want to get married.' So I said, 'Hmm, I know who's gonna film my wedding.'" Capestro said. "So Phil actually filmed me on the worst day of my life. And on the best day of my life."
"Not many people went through what we went through and survived. And it's a bond. It's a bond that can't be broken," she added. Penman agreed with Capestro on the bond and friendship that developed between them.
"That's the only good thing that came out of it, I think for me ... develop this bond. Friends," Penman said.
Capestro's story is featured in the new documentary, "Memory Box: Echoes of 9/11," a co-production of NBC News Studios and Yard 44. "Memory Box: Echoes of 9/11" will air on MSNBC on Saturday and Sunday at 10 p.m. ET and will be available to stream exclusively on Peacock. MSNBC and Peacock are part of our parent company, NBCUniversal.