Microsoft co-founder Paul Allen’s expedition team on Tuesday released the first underwater footage of the sunken destroyer USS Ward, whose captain famously radioed in on Dec. 7, 1941, “We have attacked, fired upon and dropped depth charges” on a submarine operating in Pearl Harbor’s defensive sea area.

The alert was sent about an hour before Japanese planes swooped down on Pearl Harbor. History would later show that the Ward had sunk one of five Japanese midget subs attempting to enter the harbor.

“In doing so, the Ward fired the first shot of the battle (and) the first shot of World War II in the Pacific,” retired Rear Adm. Sam Cox, head of the Naval History and Heritage Command, wrote last year.

Allen’s research vessel Petrel made earlier headlines Aug. 19 when it found the USS Indianapolis, which in 1945 delivered components of the “Little Boy” atomic bomb to Tinian Island and was subsequently sunk by a Japanese submarine. The heavy cruiser was located in the Philippine Sea in waters 18,000 feet deep.

The Petrel documented the Ward in its final resting place near Ponson Island in the Philippines and released video images just prior to the anniversary of the attack on Pearl Harbor, Allen’s USS Ward Expedition said in a release.

“The USS Ward found herself in the crucible of American history — at the intersection of a peacetime Navy and war footing. She took decisive, effective and unflinching action despite the uncertain waters. Now 76 years on, her example informs our naval posture,” Adm. Scott Swift, commander of U.S. Pacific Fleet, said in the release.

At 6:45 a.m. on Dec. 7, 1941, the Ward, crewed by Navy reservists from Minnesota, fired on the suspect submarine.

Hours earlier, at 3:42 a.m., the minesweeper USS Condor had spotted a periscope just under 2 miles from the Pearl Harbor entrance. The supply ship USS Antares also had identified the sub trying to trail her into the harbor.

The Ward’s captain, Lt. William Outerbridge, “appeared on deck wearing a kimono over his pajamas,” said Thurston Clarke in “Pearl Harbor Ghosts.” “A gunner asked him, ‘Captain, what are we going to do?’ and Outerbridge, showing a decisiveness lacking in other officers during this final hour, responded, ‘We are going to shoot.’”

The older four-stack destroyer fired guns 1 and 3, and began dropping depth charges. The shot from the No. 3 gun hit the sub at the waterline at the base of its conning tower, a later discovery would show.

At 6:53 a.m., Outerbridge radioed the 14th Naval District Headquarters in Pearl Harbor: “We have attacked, fired upon and dropped depth charges upon submarine operating in defensive sea area.”

The submarine had slipped beneath the waves. For the next hour, and until Japanese planes swarmed in the sky, skepticism was the response.

Adm. Husband E. Kimmel, head of the U.S. Pacific Fleet, didn’t believe an attack was underway because there had been false reports of submarines before.

Five 78-foot Japanese midget submarines launched from larger subs were supposed to lie submerged in Pearl Harbor and attack in concert with carrier-based airplanes.

No anti‑submarine nets were in place at Pearl Harbor, but anti‑torpedo nets were intended to prevent a submarine outside from firing torpedoes into the harbor. The attack was unsuccessful, although some of the twin 18-foot torpedoes carried by the two-man subs were fired.

The Ward was sunk on Dec. 7, 1944, exactly three years after Pearl Harbor, after being attacked by several kamikazes.

“She had been patrolling Ormoc Bay off the island of Leyte, serving as a high-speed transport for troops. She was hit at the waterline amidships by one of the attacking kamikaze. Unable to extinguish the resulting fire that was now consuming the ship, the crew was ordered to abandon ship,” the USS Ward Expedition said.

The Ward was scuttled by an accompanying ship, the USS O’Brien, then commanded, ironically, by Outerbridge, who had been on the Ward on Dec. 7, 1941, the group said.

The Petrel is a 250-foot research and exploration vessel purchased by Allen in 2016 and is capable of exploring to 6,000 meters deep, or more than 3.5 miles, according to the group.

The USS Ward’s wreckage was identified and cross-referenced with historic drawings and schematics of the ship. The survey of the Ward was part of a combined mission to document the Japanese warships that were lost during the Battle of Surigao Strait in the Philippines.

During the November expedition, the Petrel was able to capture video of the battleships Yamashiro and Fuso and destroyers Yamegumo, Asagumo and Michishio. These ships and more than 4,000 men were lost during a decisive battle on Oct. 25, 1944, considered the largest naval battle in history.