Investigators were searching for suspects Wednesday after a shooting that killed one Border Patrol agent and wounded another near the U.S.-Mexican border in Arizona.

The agents came under fire near Naco, Arizona, Tuesday after responding to a sensor that had gone off near the border, the U.S. Customs and Border Protection agency said.

Authorities identified the agent killed as 30-year-old Nicholas Ivie. A native of Provo, Utah, he joined the Border Patrol in January 2008. Ivie is survived by his wife and two young children.

"I'm just in shock right now and sad," sister-in-law Michelle Ivie told CNN affiliate KUTV. "Nick was the most tenderhearted, kind, gentle, loving person you could ever meet."

He was the youngest of five children, KUTV reported.

In a statement, his parents and brothers said: "We are extremely proud of Nick and for his service both in his community and our country. He loved what he did and he gave it his all, including his life. Our thoughts and prayers are with his wonderful wife and his two beautiful girls."

President Barack Obama called Ivie's family to offer his condolences and thank the family for Ivie's service, the White House said.

"The president told the family they are in his thoughts and prayers and made clear that his administration was doing everything it could to locate those responsible for this tragic event," a White House statement said.

The agent who was wounded was not identified. After the shooting, he was airlifted to an area hospital and with non-life-threatening injuries.

He was released from the hospital Wednesday, said Jeremy Copeland, an agent with the Tucson Sector of U.S. Border Patrol.