Updated Nov. 20 8:28 p.m.
A U.S. Border Patrol agent is dead and another is in stable condition in an El Paso hospital after responding to a call in West Texas late Saturday night.
The agents were "responding to activity" outside Van Horn on Interstate 10, according to a statement from U.S. Customs and Border Protection.
The FBI released a statement Monday night that said the two were found in a culvert adjacent to the interstate at 11:20 p.m. Saturday. They had suffered traumatic head injuries and broken bones.
Agent Rogelio Martinez died from his injuries, said Victor Velazquez, acting chief patrol agent for the Big Bend Sector, in the news release. The other agent, who has yet to be named, is in an intensive care unit in stable condition.
According to the release, the unnamed agent radioed in for help, saying the two were injured. Additional Border Patrol agents responded to the call and transported them to a Van Horn hospital. They were then airlifted to El Paso.
According to officials, Martinez, 36, was a native of El Paso. He entered service for the Border Patrol in August of 2013. He is survived by a son.
Martinez is one of at least two Border Patrol agents who have died in the line of duty this year, according to the CBP website.
The FBI is leading the investigation along with the Culbertson County Sheriff's Department, Border Patrol, and the Office of the Inspector General.
In response to the incident, President Trump tweeted, "We will seek out and bring to justice those responsible. We will, and must, build the Wall!"
Border Patrol Officer killed at Southern Border, another badly hurt. We will seek out and bring to justice those responsible. We will, and must, build the Wall!
— Donald J. Trump (@realDonaldTrump) November 20, 2017