Officials identify 2 National Guard soldiers, Border Patrol agent killed in helicopter crash near southern border

The identities of two National Guard members and one Border Patrol agent who were killed in a helicopter crash near the U.S.-Mexico border were released Sunday by respective officials.

The National Guard Lakota UH-72 helicopter crashed just before 4 p.m. local time on Friday along the U.S.-Mexico border near Rio Grande City, Texas, the Department of Defense's Joint Task Force North said. A third National Guardsman was injured in the crash, officials said.

Chief Warrant Officer 2 Casey Frankoski, 28, of Rensselaer, New York, and Chief Warrant Officer 2 John Grassia, 30, of Schenectady, died in the crash, the National Guard Bureau said. The identity of the injured soldier was not released.

Border Patrol Agent Chris Luna also died in the crash, Homeland Security Secretary Alejandro Mayorkas said.

Mayorkas said his thoughts and "deepest condolences" are with the Border Patrol agent and National Guard members' families after the deadly incident.

"Every single day, our Border Patrol Agents place themselves in harm's way so that the rest of us can be safe and secure," Mayorkas said in a press release Sunday. "My thoughts, and the deepest condolences of our Department, are with Agent Luna's family, loved ones and colleagues, and with those of the National Guardsmen who lost their lives."

The cause of the crash is under investigation, according to officials.

The helicopter crash occurred during routine operations while assigned to the federal Southwest border support mission, officials said.

President Joe Biden honored those who were killed Saturday, saying in a statement, "Their sacrifice will never be forgotten."

"These brave Americans dedicated their lives to protecting our nation," Biden said. "They signed up knowing the risks and believing in the mission of serving their fellow Americans by keeping our nation safe. Our gratitude is profound, and their sacrifice will never be forgotten."

The president added, "We extend our deepest condolences to their families and loved ones, as well as their colleagues in the National Guard and U.S. Border Patrol. We pray for the injured Guardsman's swift recovery."

ABC News' Luis Martinez, Shannon Crawford and Luke Barr contributed to this report.