Pulitzer-winning journalist Ernie Pyle described the scene. “A new sound gradually droned into our ears — a gigantic faraway surge of doom-like sound. It was the heavies. They came on in flights of 12, three flights to a group and in groups stretched out across the sky. Their march across the sky was slow and studied. I’ve never known anything that had about it the aura of such a ghastly restlessness.”

The heavies carpeted the front line with more than 12 million pounds of bombs, turning the land into a cratered moonscape.

German 88-millimeter flak guns fired back at the bombers, shooting down five — but the guns were spotted by low-flying L-4 observation plans, which directed artillery batteries to silence them. More than 50,000 shells were fired by no fewer than 1,000 artillery pieces in 47 artillery battalions to support the bombardment.

To cap it off, another wave of 350 P-47 Thunderbolt fighter bombers and 396 B-26 Marauder medium bombers pounded the German lines, many of them unloading canisters of napalm.

Once again, the bombers flew perpendicular to the allied lines. Many used the smoke from earlier bombing as a guide for where to drop their bombs, but unfortunately the wind began blowing the smoke toward the north. This time, 77 dropped too soon.

A 4th Infantry Division battalion commander described the feeling of dread. “The dive bombers came in beautifully, dropped their bombs right in front us just where they belonged. Then the first group of heavies dropped theirs. The next wave came in closer, the next one closer, still closer. Then they came right on top of us. The shock was awful.”

Lt. Gen. Leslie McNair, one of the chief brains behind the Army’s training program and doctrine, had advanced to a foxhole at the tip of the attack in order to boost morale.

“The ground belched, shook and spewed dirt to the sky,” Bradley wrote in his autobiography A General’s Life. “Scores of our troops were hit, their bodies flung from slit trenches. Doughboys were dazed and frightened … A bomb landed squarely on McNair in a slit trench and threw his body 60 feet and mangled it beyond recognition except for the three stars on his collar.

The short bombing killed 111 American soldiers and wounded 490, the majority in the 30th Division. The entire headquarters staff of a battalion in its 47th regiment was wiped out save for the commander.

Eisenhower was so furious that he declared he would never employ strategic bombers on tactical targets again. But the German troops suffered even worse from the bombing.

“The long duration of the raid, without any chance of fighting back, created depression, a feeling of powerlessness and weakness and inferiority,” Gen. Fritz Bayerlein recounted:

Some of the soldiers went crazy; others remained prostrate on the ground, incapable of doing anything. I found myself personally at the heart of the bombardment on the 24th and 25th July, and I was enormously affected. I, who always found myself in the most exposed places in war, it was my worst experience ever.

The well-dug-in infantry were crushed in their foxholes by the bombs, killed and buried by the explosions …

The bombardment zone was transformed into a field of craters in which not a single human remained alive. Tanks and cannons were destroyed or over turned without any hope of being recovered because all of the roads were blocked. Once the bombardment had begun, all telephone lines were cut. Because most of the command posts were caught in the bombardment, there was not any radio communication, either.

Upon receiving orders from Kluge to hold the line, Bayerlein famously responded, “Out in front, everyone is holding out. Everyone. My grenadiers and my engineers and my tank crews — they’re all holding their ground. Not a single man is leaving his post They’re lying silent in their foxholes because they are dead.”

It is estimated 1,000 Germans were killed by the bombardment. The rookie German parachute regiment simply evaporated, its survivors fleeing or surrendering. The Panzer Lehr Division had only a dozen operational tanks left.

The Infantry Go In:

The American infantrymen were badly shaken by the friendly bombing but were swiftly thrust out into the attack — and soon had the impression the German were unaffected by the bombardment. Machine-gun fire stitched across their advance, and surviving German tanks and artillery were soon raining shells upon them.

The 9th Infantry Division on the west flank made little progress as it attacked through wetlands towards the village of Marigny. The 30th Infantry Division on the east flank founds it advance blocked by three deadly Panther tanks. An American tank attack left three Shermans in flames for little gain — it wasn’t until midnight that the 30th secured its minimum objective for the day, the nearby village of Hébécrevon.

The 4th Division in the center made the most progress. One of its battalions stalled facing two Panzer IV tanks supported by infantry. G.I.s eventually knocked out the tanks with bazookas, and a late-arriving company of 18 Sherman tanks blasted out the infantry. The 4th made it to the ruins of Saint Chapelle-le-Juger that evening.

In the first day of Cobra, the VII Corps had only advanced 2,000 meters. The Germans were still fighting back as hard as ever. Collins wasn’t sure if he needed to give the infantry more time to clear out the German defenses, or if he should send his armor divisions out to attempt a breakthrough.

If deployed too early, the tanks might get bogged down in ambushes and cause traffic jams on the limited road network, bringing an end to the Americans hope of a break out.

Collins had noted that the German defenders were no longer coordinated in a single defensive line. He decided to unleash the armor. By the morning of July 27, tanks from the 2nd and 3rd Armored Division were rolling down to the front line.

The armor breaks through

Collins had gambled well. Only a thin crust of German defenders fighting from isolated strongpoints remained. They had no reserves behind them. Supporting attacks by American and Canadian troops to the west and east respectively had pinned down other German units in Normandy.

While Combat Command B of the 3rd Armored Division wasn’t able to secure Marigny to the west, to the east the 2nd Armored roared ahead at full speed. At Saint Gilles it encountered four German Panzer IVs and a Sturmgeschutzassault gun, but a combination of Sherman tanks and tactical air strikes dealt with the enemy armor.

By the end of the day, the 2nd had advanced 12 kilometers at cost of just three tanks. There were no enemy units left in front of it.

Field Marshall Günther von Kluge, commander of German forces in Western Europe, realized the gravity of the situation — he ordered troops along west of the breakthrough to retreat 30 kilometers to avoid being pinched off against the French coast. But the order came too late.

By July 28, the 2nd Armored Division managed to encircle the retreating Germans around Coutance, cutting off the remaining German units on the Cotentin peninsula. American tanks rolled by Bayerlein’s headquarters. “My division no longer effectively exists,” Bayerlein reported to his superiors.

The commander of the German 7th Army had to dodge fire from American Greyhound armored cars. Christian Tychsen, the chief of the 2nd S.S. Panzer Division Das Reich who had ordered the reprisal execution of 99 innocent French civilians in Tulle a month earlier, was killed when his Schwimmwagenattempted to run a road block of the 2nd Armored Division.

That night, the encircled German troops — including dozens of tanks — attempted to slip through the American lines. Some evaded the net — others fought frantic battles against American blocking forces.

In one incident, a German tank column caused an American infantry company to route. As the German tanks pursued, they bumped into the bivouac of M7 Priest self-propelled howitzers of the 78th Armored Field Artillery. Generally used to fire indirectly at distant targets, the 78th lowered it guns for direct fire and knocked out seven Panzer IVs, causing the remainder to retreat.

On the other hand, Hans Schabschneider, a sergeant in a German munitions unit, managed not only to lead his group safely, but captured 120 American soldiers and 12 trucks while doing so.

Overall, over 7,500 German troops were captured or killed in the Roncey pocket, and over 250 vehicles and 100 tanks were found destroyed or abandoned. On July 31, American units driving south seized Avranches, giving the Allies free range of France’s western coastline, including Brittany.

On Aug. 1, Patton’s Third Army roared through the breakthrough and turnedeast, seeking to encircle the German troops engaged with British and Canadian Forces. Soon the entire German front line came unglued as divisions retreated in a desperate effort to avoid being caught in the Falaise Pocket.

Patton’s Army continued its historic advance, liberating more than half of France, including the city of Paris on Aug. 25. After troubled campaigns in North Africa and Italy, the U.S. Army’s moment of glory had finally come.