Medal of Honor: William J. O’Brien – World War II – June 20 to July 7, 1944

Name: William J. O’Brien
Rank: Lieutenant Colonel
Branch: U.S. Army
War: World War II
Unit: 1st Battalion, 105th Infantry Regiment, 27th Infantry Division
Date of Action: June 20 – July 7, 1944
Location: Saipan, Mariana Islands

Summary of Action

Between 20 June and 7 July 1944, Lieutenant Colonel William J. O’Brien displayed extraordinary heroism while commanding the 1st Battalion, 105th Infantry Regiment during the bitter campaign for Saipan.

Early in the fighting, assault elements of his battalion were pinned down by intense Japanese fire from a heavily fortified position. O’Brien ordered tanks forward to support the attack, but enemy fire forced the tank crews to close their hatches, causing the vehicles to lose direction and begin firing dangerously close to American troops.

Without hesitation, O’Brien ran through enemy fire toward the lead tank, striking its hull with his pistol to gain the crew’s attention. Climbing onto the tank while fully exposed to enemy fire, he personally directed the armored assault until the strongpoint was destroyed.

Several days later, during the battle for a heavily defended ridge near Donnay, O’Brien organized a double envelopment involving two battalions and personally supervised the attack.

Crossing nearly 1,200 yards of sniper-infested terrain alone, he reached one of his stalled platoons and, taking only four soldiers with him, entered a narrow ravine behind the Japanese position. The small force destroyed or drove off the defenders, capturing five machine guns and a 77-mm field gun.

After organizing the captured ground for night defense, O’Brien remained with his men and directed the successful repulse of repeated enemy counterattacks.

On 7 July 1944, his battalion became one of the principal targets of the largest Japanese banzai attack of the Pacific War. An estimated force of 3,000 to 5,000 Japanese soldiers struck the American lines, producing savage hand-to-hand fighting along the entire front.

As casualties mounted and ammunition supplies dwindled, O’Brien refused to leave the front line.

Walking calmly among his men amid the fighting, he fired a pistol in each hand while encouraging his soldiers and strengthening their resolve.

Even after being seriously wounded, he declined evacuation.

When his pistol ammunition was exhausted, he climbed onto a jeep-mounted .50-caliber machine gun and continued firing directly into the attacking enemy.

The last time he was seen alive, Lieutenant Colonel O’Brien stood upright behind the machine gun, firing into the advancing Japanese as they closed around his position.

When his body was later recovered, numerous enemy dead lay around him.

His courage, leadership, and determination inspired his battalion during one of the most desperate battles of the Pacific War and reflected the highest traditions of the United States Army.

Medal of Honor Citation

O’BRIEN, WILLIAM J.

Rank and organization: Lieutenant Colonel, U.S. Army, 1st Battalion, 105th Infantry Regiment, 27th Infantry Division.

Place and date: Saipan, Mariana Islands, 20 June through 7 July 1944.

Entered service at: Troy, New York.

Birth: Troy, New York.

G.O. No.: 35, 9 May 1945.

Citation:

For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty at Saipan, Marianas Islands, from 20 June through 7 July 1944. When assault elements of his platoon were held up by intense enemy fire, Lt. Col. O’Brien ordered 3 tanks to precede the assault companies in an attempt to knock out the strongpoint. Due to direct enemy fire the tanks’ turrets were closed, causing the tanks to lose direction and to fire into our own troops. Lt. Col. O’Brien, with complete disregard for his own safety, dashed into full view of the enemy and ran to the leader’s tank, and pounded on the tank with his pistol butt to attract 2 of the tank’s crew and, mounting the tank fully exposed to enemy fire, Lt. Col. O’Brien personally directed the assault until the enemy strongpoint had been liquidated.

On 28 June 1944, while his platoon was attempting to take a bitterly defended high ridge in the vicinity of Donnay, Lt. Col. O’Brien arranged to capture the ridge by a double envelopment movement of 2 large combat battalions. He personally took control of the maneuver. Lt. Col. O’Brien crossed 1,200 yards of sniper-infested underbrush alone to arrive at a point where 1 of his platoons was being held up by the enemy. Leaving some men to contain the enemy he personally led 4 men into a narrow ravine behind, and killed or drove off all the Japanese manning that strongpoint. In this action he captured 5 machineguns and one 77-mm fieldpiece. Lt. Col. O’Brien then organized the 2 platoons for night defense and against repeated counterattacks directed them.

On 7 July 1944 his battalion and another battalion were attacked by an overwhelming enemy force estimated at between 3,000 and 5,000 Japanese. With bloody hand-to-hand fighting in progress everywhere, their forward positions were finally overrun by the sheer weight of enemy numbers. With many casualties and ammunition running low, Lt. Col. O’Brien refused to leave the front lines. Striding up and down the lines, he fired at the enemy with a pistol in each hand and his presence bolstered the spirits of the men, encouraged them in their fight, and sustained them in their heroic stand. Even after he was seriously wounded, Lt. Col. O’Brien refused to be evacuated and after his pistol ammunition was exhausted, he manned a .50-caliber machine gun mounted on a jeep and continued firing. When last seen alive he was standing upright firing into the Japanese hordes that were then enveloping him. Some time later his body was found surrounded by enemy he had killed. His valor was consistent with the highest traditions of the service.