They were also there in Newtown, Oklahoma City and in New York City on 9/11.

They’re police, firemen, paramedics, doctors, nurses, friends, neighbors – hundreds of typically anonymous bystanders who happen to be in the area during a tragedy like the one we faced Monday at the end of the Boston Marathon.

They’re like Carlos Arredondo who said he acted instinctively. When the first bomb went off, Arredondo jumped a security fence and, seeing a young man with both legs gone below the knee, told him to “Stay still. The ambulance is here. Try to relax.”

The Costa Rica native, who’s been living in the United States since 1980, was one of many eyewitnesses who ran toward the smoke and chaos instead of running away.

“I did my duty,” Arredondo said later in an interview.

Blocks away from the explosion, Army veteran Bruce Mendelsohn said he was knocked out of his seat by the blast. But Mendelsohn picked himself up and headed toward the scene to help.

“I was with my brother, who had just finished the marathon, and I yelled at him to get all the people back away from the windows,” Mendelsohn told Good Morning, America.

ABC News reported that “former New England Patriots player Joe Andruzzi, who was there in support of his cancer foundation, was seen carrying an injured woman to safety.”

“One witness tweeted a photo of dozens of ambulances lining the streets with the caption, ‘This is what a hero looks like.’

“Another man tweeted, ‘My boss’ brother was at the Boston Marathon and he said he carried a five-year-old who had lost her legs five blocks to an ambulance.’ ”

Those and many more were there in force to help whoever needed it.

There were no Republicans, Democrats, Independents or Tea Partiers there that day. No Protestants, Catholics, Jews, or Islamists. Only Americans.

“That’s what Americans do in times of crisis,” Suffolk County District Attorney Daniel Conley, a Boston mayoral candidate, said. “We come together and we help one another. Moments like these, terrible as they are, don’t show our weakness, they show our strength.”

And that strength is compassion – seeing ourselves in another.

During times of great crisis, the spirit of America is its people acting outside themselves. It’s the same spirit that has carried us through everything from our first American crisis to a Great Depression; from 9/11 to Hurricane Katrina; from Columbine to Newtown. During those times, Americans have worked together to overcome any challenge, every challenge they have faced.

That’s what we do. That’s who we are.