FOR 14-YEAR-OLD Luis Iriondo Aurtenetxea and the other inhabitants of the Basque capital of Guernica, April 27, 1937 should have been just another Monday market day.

At 4:30 p.m., most of the city’s 7,000 residents were in the streets shopping beneath the late afternoon sunshine. Although much of Spain had been rocked by civil war for nearly a year, this particular Republican enclave had so far been spared.

Iriondo recalled how suddenly the bells in the local church began to peal signalling to residents that hostile aircraft were approaching. Locals knew the sound well — they’d heard it on several occasions in recent days. But each so far time, the warning had proved to be a false alarm.

“No one took it seriously,” Iriondo told the German magazine Spiegel in 2012.

He grudgingly took shelter at the urging of an overly cautious elder.

“If I hadn’t, I probably wouldn’t be alive,” he admitted.

Within moments, the skies above Guernica were filled with warplanes. Three-dozen bombs fell onto the city centre. Iriondo recalls the relentless earsplitting cacophony of explosions and the violent shockwaves that assaulted his body as the weapons blasted apart nearby buildings. Smoke and dust rapidly filled the dank cellar.

“We thought we would suffocate. One of us tried to light a match, but there wasn’t enough oxygen,” Iriondo told the magazine.

After 30 minutes of hell, the bombardment ended. But the calm didn’t last; the planes soon returned with another deadly payload. By the time it was all over, Guernica was in ruins. Three-quarters of the city’s buildings were destroyed and at least 126 lay dead beneath the debris.

Tragically, the infamous raid would become a blueprint for the massive strategic bombing campaigns of World War Two and beyond. Yet, much of the devastation that day was caused by relatively “light” 110-lb. bombs. The bombardments of future wars would see much heavier ordnance dropped than that. In fact, some of the bombs used later would be so massive they’d make the weapons released over Guernica look like mere firecrackers by comparison. Consider these outsized explosives:

The Gotha Bomb

The first bombs ever dropped from aircraft were hand-sized weapons. As early as the 1911 Turkish War, aviators tossed the small charges from their cockpits onto the enemy below. During the First World War, air forces began releasing larger, purpose-built ordnance from increasingly sophisticated aircraft. On Feb. 16, 1918, a German Gotha heavy bomber taking part in a raid on England loosed a 2,200-lb. bomb, the biggest in history up to that point, onto the city of London. The record-breaking weapon struck the Royal Hospital in Chelsea.

---

The SC 2500

Twenty-two years later, German bombs would again be raining down on London, the largest of which was the SC 1800 Satan. The 4,000-lb. weapon was designed to be carried by the Heinkel He-111. The Nazi SC 2500 was even larger. At 5,500-lbs, it was the heaviest German free-fall bomb of the war.

---

Upkeep

Britain’s famous Dam Busters used 19 specially fitted Avro Lancasters to deliver the top-secret water-skimming Vickers Type 464 Upkeep bombs onto the Möhne and Edersee dams in Germany’s Ruhr Valley. The cylindrical weapons weighed in at an impressive 9,250-lbs — enough to blast a hole though several feet of concrete.

---

The Tallboy

The following year, the RAF unveiled its 12,000-lb. Tallboy bomb. The weapons, of which more than 300 were manufactured, were used in nearly three-dozen raids on fortified targets throughout Nazi-occupied Europe including V-1 and V-2 launch sites, railroad tunnels and U-boat pens. The most famous Tallboy target was the German battleship Tirpitz. It was damaged and later destroyed by Lancasters armed with the enormous weapons.

---

Grand Slam

Even the Tallboy was dwarfed by Britain’s Grand Slam, a massive 22,000-lb. “earthquake bomb” designed to crack the toughest nuts in the Third Reich. A total of 42 of the outsized weapons were used in the final two months of the war. They were dropped on German viaducts, bridges and submarine pens with devastating effect.

---

Cloudmaker

The United States doubled down on the Grand Slam concept in 1944 began testing a devastating demolition bomb known as the T-12 Cloudmaker. The 43,000-lb. weapon was aerodynamically engineered to penetrate deep into a structure before going off. None were ever dropped in anger and the program was discontinued in 1948.

---

Tarzon

The 13,000-lb. American VB-13 Tarzon had a fraction of the Cloudmaker’s mass, but what it lacked in raw power it made up for with precision. The weapon was designed to be guided onto its target by radio, making it one of the United States’ first ‘smart bombs’. More than 30 were dropped by Boeing B-29s during the Korean War. Targets included communist power plants and bridges.

---

Cutting Daisies

The BLU-82 “Daisy Cutter” was developed during the Vietnam War not to destroy strategic targets, but rather to carve impromptu landing zones out of the dense jungles of South East Asia. The 15,000-lb. weapon was sized to fit into the cargo bay of a C-130 Hercules or underneath a CH-54 Flying Crane helicopter. Once dropped, the bomb would descended gently towards the earth by parachute. Sensors would detonate the high-explosive payload at treetop level, leveling vegetation for up to nearly 1 kilometer in every direction without leaving a crater. It was used in the closing days of the Vietnam War, as well as the 1991 Gulf War and also against Taliban insurgents sheltering in the caves of southern Afghanistan in 2001.

---

 The Mother of All Bombs

The American GBU-43/B Massive Ordnance Air Blast (aka “the Mother of All Bombs”) marked a return to the massive earthquake weapons of the Second World War. Billed in 2002 as the largest non-nuclear weapon in the U.S. arsenal (or anyone’s for that matter), the 10,000-lb. bomb was engineered to deliver an explosive yield equivalent to 11 tons (22,000 lbs.) of TNT. A single MOAB was deployed with U.S. forces to Iraq in 2003 although never used. There are reportedly 15 currently in existence.

---

Bunker Buster

Based on the premise that when it comes to bunker busting, bigger is always better, in 2011 the Pentagon added the 30,000-lb. GBU-57A/B Massive Ordnance Penetrator to its inventory. Boeing designed the GPS-guided weapon to pierce hardened surfaces and borrow deep into the earth by the sheer force of its own momentum before detonating. The USAF maintains a stockpile of 20.

---

Big Daddy

Never one to be outdone, in 2007 Russia announced it had developed what it described as the Aviation Thermobaric Bomb of Increased Power (ATBIP) or the “Father of All Bombs”. The 15,000-lb. air dropped weapon packs a punch equal to 44 tons of TNT – that’s 80,000 lbs. of firepower. It’s considered to be the largest non-nuclear weapon ever devised. Moscow reports that it has 100 of the outsized explosive devices.

---