BOSTON - Sisters Sarah Bush and Laura Hall remember exactly where they were on April 20, 1999.
Survivors of the Columbine shooting, the sisters are preparing to run the Boston Marathon together, having found solace and calm in running.
Sarah Hall, a 16-year-old sophomore, was taking a test in math class. Laura Bush, a 14-year-old freshman, was eating lunch in the school's lunchroom.
"It was probably a few minutes into the period, and we heard an explosion. And at that point, Coach Ortiz, our baseball coach, ran through to each room and told everybody we need to get out," Bush said.
Bush was able to escape through the front door; her sister took shelter with dozens of others in the school's choir room.
"We ended up with 30 or 40 other students, barricading ourselves in the choir office. And we were locked in there for four to 4 1/2 hours before we rescued by the SWAT team," Hall said.
On the way out, Hall stepped over the body of Daniel Rohrbough, one of the 12 students killed that day.
It would be years before the sisters could talk openly about what they saw.
"Not even just to each other," Hall said. "But to anybody. It took many, many years."
Through the pain, the two were able to find healing in a shared activity: running. Bush was already a member of the track team at the time of the shooting.
"It helped me just be able to find a few moments of peace and quiet," she said.
It wasn't long before the two were running together as adults.
"Each year, each anniversary, we feel a little stronger," Hall said. "And I think running, and running marathons has taught us that we can do really hard things."
This year, they're tackling their biggest run yet at the Boston Marathon.
"It's really neat that the 20th anniversary has come up to be so close to this marathon," Hall said. "We feel like all the stars aligned for us, and it's been amazing."
The sisters said they aren't sure who will finish the race first.
"We'll give a high-five at the beginning, and a hug at the end," Bush said. "We'll be waiting for each other. We're not sure who will finish first, and maybe we'll find each other and hold hands the rest of the way, but we want each other to do the best they can."