A chorus of Democratic lawmakers have joined the education secretary, Betsy DeVos, in calling for Congress to act after a gunman killed 17 people at a high school in Parkland, Fla.

In a letter on Friday, all 17 Democrats on the House Education Committee urged Representative Virginia Foxx, the committee’s chairwoman, to convene hearings on school shootings, describing them as a “public health epidemic.” The panel has not addressed the issue since February 2013 — two months after a shooting at Sandy Hook Elementary School in Connecticut left 20 first graders and six adults dead, they said.

“Wednesday’s preventable tragedy at Marjory Stoneman Douglas High School in Parkland, Florida, resulted in the deaths of at least 17 students and faculty,” the letter said. “Sadly, since the mass shooting at Sandy Hook Elementary School five years ago, more than 430 people have been shot in over 230 school shootings.”

The letter adds pressure on Congress to address the pervasiveness of school shootings across the country, an issue that Ms. DeVos raised during an interview on Thursday with the conservative radio host Hugh Hewitt.