When 14 students and 3 teachers were killed Feb. 14 at Marjory Stoneman Douglas High School in Parkland, Florida, by a 19-year-old using an AR-15 assault-style rifle, Army veteran Dennis Magnasco spoke out.

“It shook me to my core because it sounded like combat,” Magnasco said. “I had this feeling of, ‘This isn’t right.’ ”

Magnasco said he’s a combat veteran, a gun owner and a staunch supporter of the Second Amendment. And he’s ready for gun reform.

“I recognize the power of firearms. I’ve seen what they can do,” Magnasco said. “And it makes me sick to know that we have high school kids seeing this in their schools.”

He tweeted a message to that effect Feb. 18, along with the hashtag #VetsForGunReform and a photo of himself and other soldiers in Afghanistan toting M4 carbine rifles.

A group of veterans— some staffers for elected officials, some policymakers and some advocates, urging Congress to reform the access to and sale of firearms, from fixing and expanding background checks to limiting the style of guns sold.

“A lot of us have always been passionate about this issue,” said Andrea Goldstein, a former Navy lieutenant who served with expeditionary forces in multiple war zones.

“We want to make our expertise and position very clear, hoping that we can help inform decision-makers,” she said. “Ultimately, lawmakers have decisions to make, and we hope they make decisions that keep our children safe.”

Trump introduced his idea to arm some of the country’s teachers with concealed weapons to fortify schools against future mass killings.

The combat veterans described the idea as “preposterous” and “absurd.”

“Teachers should be teaching, not out on the rifle range,” Goldstein said. “And I absolutely reject the idea that increasing guns in our schools is going to solve the problem.”