By February 1944, Riordan was a Second Lieutenant with the 133d Infantry Regiment, part of the 34th Infantry Division. Riordan and the "Red Bull" division were locked in combat in Italy in the early phases of the Battle of Monte Cassino.
On February 3, 1944, Riordan led his assault platoon up a hill heavily defended by the Nazis. When their advance was stopped, he took an exposed position from which he could break up a key defensive bunker with a hand grenade. Five days later on February 8th, Riordan's platoon was ordered to take an enemy strongpoint in the town, and while once again leading from the front, Riordan was cut off from the rest of his men, but nonetheless kept up the assault and inspired his men to carry on the attack by his lone courage and sacrifice.
Several months later, the Army posthumously recognized the young, brave lieutenant with the Medal of Honor.
From Medal of Honor Citations for World War II (M-S):
|Photo from Military Times' Hall of Valor|
Rank and organization: Second Lieutenant, U.S. Army, 34th Infantry Division
Place and date: Near Cassino, Italy, 3-8 February 1944
Entered service at. Kansas City, Mo.
G.O. No.. 74, 11 September 1944
Citation: For conspicuous gallantry and intrepidity above and beyond the call of duty. In the attack on the approaches to the city of Cassino on 3 February 1944, 2d Lt. Riordan led 1 of the assault platoons. Attacking Hill 175, his command was pinned down by enemy machinegun fire from the hill and from a pillbox about 45 yards to the right of the hill. In the face of intense fire, 2d Lt. Riordan moved out in full view of the enemy gunners to reach a position from where he could throw a handgrenade into the pillbox. Then, getting to his knees, he hurled the grenade approximately 45 yards, scoring a direct hit. The grenade killed 1 and wounded the other 2 Germans in the nest and silenced the gun. Another soldier then cleaned out the enemy pillboxes on the hill itself, and the company took its objective. Continuing the assault into Cassino itself on 8 February 1944, 2d Lt. Riordan and his platoon were given the mission of taking the city jail house, one of the enemy's several strongpoints. Again 2d Lt. Riordan took the lead and managed to get through the ring of enemy fire covering the approaches and reached the building. His platoon, however, could not get through the intense fire and was cut off. 2d Lt. Riordan, aware that his men were unable to follow, determined to carry on single-handed, but the numerically superior enemy force was too much for him to overcome, and he was killed by enemy small-arms fire after disposing of at least 2 of the defenders. 2d Lt. Riordan's bravery and extraordinary heroism in the face of almost certain death were an inspiration to his men and exemplify the highest traditions of the U.S. Armed Forces.
Lieutenant Riordan was engaged to Miss Dolores Gates at the time of his death. To honor her lost fiance's courage and memory, she enlisted in the United States Navy's WAVES. Riordan's remains were repatriated to the United States and laid to rest in the Mt. Olivet Cemetery in Raytown, Missouri.
The 34th Infantry Division is a present-day formation of the National Guard comprised of Guardsmen predominately from Iowa and Minnesota.
Blogger's Note: I chose to post the story of Lieutenant Riordan in the middle of the specific dates of his Medal of Honor actions to alleviate conflicts in honoring other World War II MoH recipients!