WASHINGTON ― Lawmakers are expected to meet Tuesday to broadly discuss modernizing the military’s munitions production, but the hearing follows a series of explosions and fires that have killed and injured nearly a dozen workers at munition plants in recent years and led to a previously unreported investigation by the House Armed Services Committee.

The hearing, before the Subcommittee on Tactical Air and Land Forces, comes as Congress weighs legislation that would increase oversight of the military’s suppliers by the Pentagon and Congress. Lawmakers are also considering an independent review of the enterprise.

The handful of ammunition facilities around the country are largely government-owned, contractor-operated ― some with infrastructure that dates back to World War II. The work at these facilities are extremely dangerous, with tragic mishaps over the last few years occurring at locations operated by Orbital ATK, AMTEC Less-Lethal Systems and BAE Systems.

The deaths and injuries spurred a bipartisan, six-month investigation conducted by the House Armed Services Committee that covered production, storage, transportation and demilitarization.

“We said that’s a lot of mishaps to be occurring in these industrial facilities in such a short time span,” a committee aide told Defense News. “Let’s pull the thread and see what’s going on there. From there it’s spiraled into looking at the whole munitions enterprise, from production through demilitarization and disposal of weapons.”

A separate audit of the Defense Department’s transportation practices for arms, ammunition and explosives released in March faulted the department for failing to properly track thousands of shipments by truck and rail, which exposed the public to materiel that were “stolen, damaged, exploded, ignited, or spilled across public highways.” The Pentagon’s inspector general also found that commercial carriers did not always comply with safety regulations.

Assistant secretary of the Army for acquisition, logistics and technology, Bruce Jette, and the head of Army Materiel Command, Gen. Edward Daly, are set to testify at Tuesday’s hearing.

In a statement to Defense News, Daly said modernization of the ammunition industrial base is critical to protecting the health and safety of its skilled and dedicated workforce.

“Safety is our top priority when manufacturing, handling, storing and demilitarizing munitions and associated materials with inherently dangerous operations and processes in aging infrastructure," Daly said.

"With more than $3.2 billion invested since 2009, we are focused on a comprehensive, holistic modernization strategy that moves us toward our envisioned end-state: state-of-the-art manufacturing processes and machinery that have built-in safety standards across our ammunition industrial base.”

Under language in the House-passed defense policy bill, a federally funded research entity would review critical points of failure in the military’s munitions enterprise and industrial base. That entity would also report on specific mishaps and waivers granted to facilities that didn’t comply with safety regulations.

Committee aides said they became interested in where Congress could invest more money to shore up weaknesses or empower the Department of Defense Explosive Safety Board, which sets safety standards and conducts some safety investigations.

“We looked at it soup to nuts and saw a number of issues: a lack of clear reporting on safety issues and safety waivers,” the committee aide said. “We’re trying to an additional spotlight on that.”

The House’s version of the bill would withhold 75 percent of the board’s budget until all board member positions, including the chair, are filled by a military officer with relevant experience. The bill would enshrine in law the responsibilities of the board and its chairman.

The proposed language is subject to negotiations between the House and Senate to reconcile their competing versions of the 2021 National Defense Authorization Act.

Jen Judson in Washington, D.C., contributed to this report.