There it was on the screen, tragic and terrifying, another senseless act of cowardice. This time in Boston.
Like everyone else Monday, I was upset, angry and at a loss for words.
So I called two people who have been through this before.
Tom Frost of Rancho Santa Margarita, who lost his daughter Sept. 11, 2001.
And Kevin Danni of Pasadena, who survived those same attacks in dramatic fashion.
I'll start with Frost, who was at work Monday morning when his phone rang.
"My cousin called from New York to make sure I was OK," said Frost, who operates a Santa Ana substation for Southern California Edison.
Frost had run the Boston Marathon in the past, and his cousin wanted to make sure Frost wasn't among the fallen on Monday.
Frost hadn't heard until then about the explosion at the finish line, but he quickly turned on a TV, saw the chaos and debris, and was flooded with emotion. In 1999, the first time he ran the Boston Marathon, his daughter, Lisa, cheered him on. She was a student at Boston University and went on to graduate with honors. Two years later, the 22-year-old communications major was headed back home to California when her hijacked plane, American Airlines Flight 11, crashed into the first tower in New York.
"Not a single day goes by when I don't think of her," said Frost, who ran the Boston marathon again in 2002, this time in his daughter's memory.
On Monday, he saw the runners and spectators on the ground in Boston, with people rushing to their aid. He saw the restaurant where he had eaten dinner with Lisa on the day she graduated, and he learned that an 8-year-old boy had been killed.
"That cuts to the heart," said Frost. "There are parents, like myself, who are going to be grieving for a child they'll never see again, and it's the hardest thing in the world to do."
Regardless of who was responsible for Monday's unthinkable attack, it was a reminder of the depths of human darkness. But Frost says he can't dwell on that.
"One week after 9/11, I had a parent come up to me and say, 'You know, Tom, I lost my daughter in a drunk driving accident. It was in all the papers, but then it was gone and I never had to hear about it again. But you're going to have to hear about it over and over again.'"
The comment was meant in sympathy, from someone who understood that 9/11 would forever be a reminder of our fragility, the anniversaries marked, the horror relived. But Frost sees that as a way to keep telling his daughter's story. Terrorists took Lisa's life, but they did not take the goodness and optimism she represented. Lisa was a Boston Marathon volunteer and a peer counselor and summer orientation leader at school.
"She was huge into community service," said Frost, who makes monthly pickups at the SFS Food Bank in Garden Grove and delivers his cargo to the Community Action Partnership of Orange County, which distributes food to needy families.
"It's something I do to remember my daughter," said Frost. "I think if we all gave back to the community, the world would be a better place, and we saw that in Boston. We saw everybody rallying. Everyone came through. The EMT people, the runners, private citizens, all of them helping out and running toward the fracas" to help.
Frost, 59, said his days of running the Boston Marathon may be over. But he will run other marathons. He runs for the escape, for the proof that he's alive and for the memory of Lisa cheering him through the streets of Boston.
"I keep telling myself life goes on. That's what I keep saying. Life goes on."
Kevin Danni, like Frost, neither dwells nor forgets. In 2001, Danni was fresh out of Occidental College and had just landed in New York, where he was training with an investment company.
His office was on the 61st floor of the south tower of the World Trade Center, and during a break, he looked out the window and shuddered.
The north tower was ablaze, but he didn't know why.
"Luckily, our manager said, 'Don't take the elevators,' " said Danni, who began making his way down the stairs with thousands of others.
"I got down to the 55th floor and that's when the second plane hit the tower 20 floors above me. Being from California, it felt like an earthquake. The building shook, the walls cracked."
At about the 30th floor, Danni said, he passed firefighters headed up the stairwell while he was headed down, and he presumes some or all of them later died trying to save lives. Danni made it out safely, then outran the dust cloud that surged through lower Manhattan when the towers disintegrated.
This past Monday, Danni heard the news about Boston while at work in Glendale and was reminded once more of our vulnerability and the preciousness of life. He checked in with his wife.
"I've got two small kids now," said Danni, "and I squeezed them a little tighter" Monday night.
When they are older, he will tell them they have to be careful and at times vigilant.
"But I also will tell my kids they have to live their lives."