It didn’t sound like much at first.

“I think the first thing we heard was a call for someone with an ankle injury at Columbine High School,” said Bill Pessemier, who in 1999 was Littleton’s fire chief. “Then it was shots fired. I was in a staff meeting at city hall, and I decided I better go see what was happening.”

What unfolded was one of the most horrific scenes Pessemier ever saw. A SWAT team commandeered one of his fire trucks to get closer to the school while Pessemier coordinated medical response.

“The patients we got to, the ones who were alive, they survived,” Pessemier said.

In the decades since the shooting stopped at Columbine, Pessemier has had time to reflect, but hasn’t come up with any big answers.

“Why did this happen?” Pessemier said. “Why does this occur in our society? There are problems with guns, with mental health care, with the way young people are brought up. And rather than bringing people together, these problems just push us apart.”

The bottom line, Pessemier said, is that we need to treat each other better.

“The people who do this are sick,” Pessemier said. “The vast majority of firefighter fatalities are preventable. I look at this the same way: Most shootings are preventable. Somebody saw something that could have led to an intervention. We’ve got to reach out to one another.”