The FBI is crediting sailors at a Texas air station with "potentially saving many innocent lives" when they thwarted what the agency has called a terrorism-related attack at their base Thursday.
"The FBI would like to recognize the bravery and heroism of the [Naval Air Station Corpus Christi] personnel who took quick action to prevent the shooter from entering the base," the agency's office tweeted Thursday.
Defense Secretary Mark Esper said that, when the gunman tried to get through the gate, he was stopped by a young sailor. The sailor, whose identity has not been released, suffered minor injuries and was released from the hospital Thursday.
"She's doing well, I understand," he told the "Today" show on Friday.
The gunman was killed, said Leah Greeves, the supervisory senior resident agent for the FBI's Corpus Christi office, in a brief Thursday press conference. No additional details about the attacker were released.
Federal, state and local law enforcement agencies are investigating the incident. The FBI has the lead, Esper said.
The gunman is not believed to have been affiliated with the Defense Department, he added.
"We hope to know more in the coming days as to what happened, what this person was motivated by," Esper said. "... But we need to let the facts come out and let the investigators do their job."
Greeves didn't say Thursday what led the FBI to determine the attack was terrorism-related. It marks the second attack on a Navy installation with ties to terrorism, following the December attack at Naval Air Station Pensacola in Florida.
That attack, which killed three sailors and injured eight others, was carried out by a Saudi officer training there who had ties to al-Qaida in the Arabian Peninsula, Justice Department officials announced this week.
"I am very concerned about both cases," Esper said on the "Today" show, detailing several new security measures that have been put into place following the Pensacola attack, including barring foreign military students from carrying weapons and limiting their base access.
There could be more policy changes, he added, as the FBI continues investigating the attacks.
"We're looking at additional measures we will take to ensure foreign-inspired terrorists do not have access to our posts, bases and installations -- and of course our country," he told Savannah Guthrie.
Officials at the FBI's Houston office say they're working nonstop to investigate this week's attack in Corpus Christi. They ask anyone with information about the incident to call 1800-CALL-FBI.
Greeves said Thursday that there could be a second person of interest at large in the community.
"If you see something, say something," she said.