On June 9, 2022, 30-year-old Joshua Robert Wallace was killed in a mass shooting at Columbia Machine in Smithsburg, Maryland. Wallace was in the company break room when a fellow employee, 23-year-old Joe Louis Esquivel, retrieved a semi-automatic handgun from his vehicle, returned to the break room, and opened fire. Two other coworkers, Mark Alan Frey, 50, and Charles Edward Minnick Jr., 31, were also killed and another employee was critically injured.

Esquivel fled in his car but was located by Maryland State Police. During a confrontation he exchanged gunfire with troopers, wounding one, and was then shot and taken into custody. Esquivel was charged with multiple offenses including counts of first- and second-degree murder, attempted first-degree murder, assault, and firearms-related charges. He later pleaded not criminally responsible and underwent a court-ordered mental health evaluation; a May 2023 report found he suffered from schizophrenia and a judge committed him to a state mental health facility.