A U.S. Customs and Border Protection agent died Sunday morning from injuries he suffered while on patrol in southwest Texas, in Culberson County.

Agent Rogelio Martinez and his partner were responding to activity while on patrol in the Big Bend Sector, which runs along the US-Mexico border.

Secretary of Homeland Security, Elaine Duke, expressed her condolences “on behalf of the quarter of a million front line officers and agents of DHS.” Additionally, on Sunday night, President Trump tweeted about the incident, writing, “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!”