He redialed. Voicemail.
Gaasch tried to make his way toward the smoke but was pushed back by police, as officials shut down the street. Sirens began wailing. People were rushing in different directions.
The couple had a room booked at the Westin Copley Place hotel, back near the finish line, and had planned to meet there afterward. Gaasch headed there, around barricades and walls of police.
Finally, at 2:57 p.m., as Gaasch neared the hotel, his phone beeped with a simple text from his wife: "We're OK."
Brannock and her sister were in far worse shape.
Nicole Gross, a 31-year-old fitness trainer, sat on the sidewalk, blood splattered all around her. The sleeves of her red shirt were in tatters, and her legs were bloodied and blackened. Other victims lay nearby.
She was taken to Brigham and Women's Hospital with a broken left leg and other injuries.
Brannock had been among the first victims rushed to Beth Israel Deaconess Medical Center, where doctors amputated her left leg below the knee. (That is the same hospital where bombing suspect Dzhokhar Tsarnaev would be taken after being captured Friday night.)
The decision Michael Gross, 32, made to step away from the sisters to get ready to photograph Downing likely spared him similar injuries. He suffered burns and lacerations.
But it wasn't until about an hour after the bombings that Downing got any word from them.
"Are you OK?" Michael Gross asked in a text message.
A local Boston couple helped Downing recover from the race and begin her search for her daughters. They let her shower and use their computer to cancel a flight that was scheduled to leave in a few hours. She borrowed a fleece and a pair of reading glasses. The couple took Downing to Brigham and Women's Hospital and waited until she was reunited with family and by her older daughter's side.
But it wasn't until 9 p.m. — six hours after the bombings and after Brannock's first surgery — that Downing learned of her younger daughter's location.
Since the bombings, Downing has shuttled between the bedsides of her daughters. Messages of support for the family — both emotional and financial — have poured in.
"I am overwhelmed with the people who have come out and given their support and prayers and offers of help," she says. "It makes me feel good, being so far away from home, that there's people doing all of this for my family."
Gaasch and his wife were scheduled to stay the night in Boston. After his past marathons, they had gone out and enjoyed the revelry of the city's bars and restaurants, where strangers buy runners drinks and the mood is jovial.
"Everyone is wearing their medal and high-fiving each other and everyone is whooping and hollering, and people are at the bars having beers," Gaasch says of years past.
In the aftermath of the blasts, however, "it was deathly quiet," he says.