Most destructive bombing of Braunschweig during Second World War 
In the early hours of 15 October 1944, No. 5 Group of the Royal Air Force (RAF) carried out the most destructive of 42 attacks on ("Brunswick") during World War II. The attack was a part of Operation Hurricane, which was designed to demonstrate the capabilities of the Allied bombing campaign. It caused a massive conflagration that developed into a firestorm, and resulted in , the city of Henry the Lion, burning continuously for two and a half days from 15 to 17 October. More than 90 percent of the mediaeval city centre was destroyed.
Raids.
The RAF first bombed on 17 August 1940, killing seven people, and the 94th Bombardment Group earned a Distinguished Service Cross for an 11 January 1944 mission against the Mühlenbau und Industrie Aktiengesellschaft (MIAG) components factory. As part of the Combined Bomber Offensive, was a regular target for (nighttime) RAF and (daytime) US attacks, including two "Big Week" attacks on 20 and 21 February 1944.
The first major British bombing of was in the night beginning 14 January 1944, when nearly 500 Lancaster bombers attacked in the face of strong defence by German fighters. Being a relatively small target, most of the bombs missed the city.
In an experimental raid, to see if bombing by radar alone (without target marking) was effective, nearly 400 heavy bombers raided during the night beginning 12 August 1944. No effective concentration of the bombs occurred, and nearby towns were bombed by mistake.
Between those dates, fast Mosquito bombers were sent on occasional nuisance raids and diversions against .
On 15 October 1944, No. 106 Squadron RAF bombed , and one of the last attacks was an attack on chemical plant in March 1945 as part of the campaign against synthetic oil production.
Braunschweig in 1944.
 was subjected to air raids despite the city being ringed by anti-aircraft guns. In January 1944, Bomber Command raids against "Stettin, Brunswick and Magdeburg" were suffering losses of 7.2 percent – more than in raids against Berlin that month. The targets included machine and munitions works, harbours, research institutions, canneries, railway stations and railway maintenance works, and the German Research Centre for Aviation. Targets near included the in Salzgitter and the Volkswagen factory in KdF-Stadt near Fallersleben. The nearby Oflag 79 prisoner-of-war camp was attacked on 24 August 1944.
Preparation for the 15 October 1944 air raid.
Purpose of the raid.
On 13 October, the RAF received orders to carry out Operation "Hurricane", to demonstrate the Allied bomber force's destructive power, and Allied air superiority. The orders included the following:
 ;templatestyles src="Template:Blockquote/styles.css" / ;In order to demonstrate to the enemy in Germany generally the overwhelming superiority of the Allied Air Forces in this theatre ... the intention is to apply within the shortest practical period the maximum effort of the Royal Air Force Bomber Command and the 8th United States Bomber Command against objectives in the densely populated Ruhr.
Operation "Hurricane" foresaw Duisburg as the main goal for the RAF's thousand or so bombers, and Cologne for the USAAF's 1,200 or so bombers. A further 233 RAF bombers were detailed for , which had about 150,000 inhabitants in October 1944.
Planning for the attack on was finalized by 15 August 1944. Darmstadt had been attacked on the night of 11 September 1944 using a new targeting technique: a fan-shaped flying formation, and the staggering of the use of explosive and incendiary bombs. Being a largely unprepared town, the resulting fires caused about 11,500 deaths. The Allies then turned their attention to .
 was to be largely destroyed, not only as an important centre of the armament industry, but also, and above all, as a place where people lived making it uninhabitable and useless. The goal, namely the greatest possible destruction, was to be achieved through detailed attack plans and careful execution, and also making careful use of the attributes of the materiel that was to be deployed. The means whereby the goal was to be reached was a firestorm, the production of which was to be no accident but developed through painstakingly detailed analysis.
On 13 October, the chief meteorologist at RAF High Wycombe advised RAF Bomber Command headquarters of the weather forecast for the weekend of 14–15 October: slight cloudiness, good visibility throughout the night, and moderate winds. The next day, Air Marshal Arthur Harris issued the orders to carry out the attack on and other cities.
RAF Bomber Command had sought in vain to inflict lasting destruction upon four times during 1944, failing each time as a result of, among other things, bad weather and strong defences. On 14 October 1944, preparations for the attack were finalized at No. 5 Group's headquarters at Morton Hall.
October 1944 raid.
The raid coincided with a British thousand-bomber raid on Duisburg, the second on that city within 24 hours, a previous British attack having been made in daylight.
The aircraft of No. 5 Group took off as planned at around 11pm on 14 October. The main force of the group were 233 four-engined Mark I and III Lancasters heavy bombers, each with a bomb load of about . The Lancasters were accompanied by 7 Mosquito fast light bombers.
The bombers bound for took a course that ran to the south to avoid the Ruhr area, which was heavily defended by anti-aircraft batteries and fighter aircraft. Near Paderborn, the force turned towards the north, overflying Hanover and proceeding to .
As was usual, the British actions for the night included a number of sorties to deceive the German defences about the true targets for the night. 141 training craft flew simulated attacks on Heligoland, 20 Mosquitos went to Hamburg, 8 to Mannheim, 16 to Berlin and 2 to Düsseldorf. They were supported by 140 special operations aircraft of 100 Group RAF, which deployed electronic warfare measures against German night-fighter defences. Strips of tinfoil (codenamed "Window") were scattered into the air in large amounts to jam the German air defence system's radar stations, thereby rendering them nearly useless. The feint against Mannheim, which German forces expected to be the main target, left the attack unopposed.
The siren signal alerting to an air raid was sounded at about 1:50am on 15 October.
Target marking.
The Mosquitos of No. 5 Group marked the target for the main force. No. 5 Group had developed its own techniques separate to the Pathfinder Force and was using "sector bombing". It used the cathedral as a reckoning point for the "master bomber" in the lead plane. Over the  – the site of Braunschweig Cathedral – a green flare was dropped, a so-called "blind marker". Other Mosquitos dropped their markers of various colours, lighting the target up. The first red flare fell south-west of the city centre. The same aircraft then dropped about 60 flares from a height of , which slowly floated down to the ground, each burning for about 3–7 minutes. Those lit markers were called (lit. 'Christmas tree') by the Germans, due to their characteristic appearance. Given the clear night, the problem-free overflight, and the flawless marking of the target, the conditions for the attack were optimal, from the British point of view.
The green marker on the served to guide the bomb aimers in all following aircraft, who flew in over it from various directions in a fan-shaped formation, whereupon they dropped their bombs.
RAF filming.
This raid on was filmed by a Lancaster of the RAF Film Production Unit, outfitted for the task with three Eyemo-type cameras. The camera plane flew over , along with the rest of the bombers, at a height of at . The time of the onset of the attack was noted as 2:33am.
A copy of the film is held by the Städtisches Museum Braunschweig. The film is accompanied by the following note:
 ;templatestyles src="Template:Blockquote/styles.css" / ;Bomber Command ... made a heavy and concentrated attack on the industrial town of Brunswick, which is one of Germany’s biggest centres for the aircraft and engineering industries. As the aircraft with the cameras runs up to the target, the fires can be seen spreading rapidly all over the city and by the time the aircraft is over the target, the whole city is ablaze and the streets can be seen clearly outlined.
The firestorm.
About of bombs were dropped on the city. First to be deployed were about 12,000 explosive bombs – so-called "blockbusters" – in a carpet bombing of the old timber-framed town centre to start the intended firestorm by smashing up the wooden houses. Blast waves blew the roofs off houses, exposing the insides, blew windowpanes out, splintered the inner structure, broke walls down, tore electricity and water supplies up, and drove firefighters and rescue service personnel into cellars and bunkers, along with damage observers.
After the wave of explosive bombs, about 200,000 phosphorus and incendiary bombs were dropped, which were designed to ignite the destroyed buildings and create the firestorm, which would still be burning long after the bombers had returned to England.
By about 3:10am, about 40 minutes after the first explosive bombs had been dropped, the attack was over. A hot mass of air rose rapidly upwards due to the powerful thermal generated by the conflagration. Cooler air rushed in to replace it, creating a windstorm. Winds blowing from all directions worsened the fires, further strengthening the winds, which became strong enough to sweep up small pieces of furniture and toss people about.
Around three and a half hours later, towards 6:30am, the firestorm reached its peak in the city core. About of historic old were going up in flames. The city's tallest church steeples – those of St. Andrew's were about tall – could be seen burning far beyond the town, and they also rained embers down over the whole city. The ruins of the city centre were littered with unexploded incendiary bombs, greatly hampering fire engines and rescue vehicles.
The city burned so intensely and brightly that the light from the fire could be seen far and wide. From all directions, helpers and firefighters thronged into the burning town to help. They came from, among other places, Hanover to the west and Helmstedt in the east, from Celle to the north and Quedlinburg to the south.
Within the 24 hours of Operation "Hurricane", the RAF dropped a total of about of bombs on Duisburg and .
Rescue of 23,000 trapped people.
About 23,000 people had sought refuge from the attack in six large bunkers and two air raid shelters in the area. While these thousands of people waited in seeming safety inside their thick-walled but quite overfilled shelters for the all-clear signal, the many fires in the city centre quickly merged into one widespread conflagration. 
The fire brigade very soon realized the threat to these people – the fire was growing ever hotter, and the oxygen in the bunkers and shelters thereby ever thinner. The danger was clearly that the victims would either suffocate for lack of oxygen if they stayed in their bunkers, or be burnt alive if they tried to leave and escape through the firestorm outside.
Towards 5am, before the firestorm had reached its full intensity, the idea of building a (lit. 'water alley') was suggested by Rudolf Prescher, lieutenant of the fire brigade. This alley would allow the people to flee their shelters for safer areas of the city. It consisted of a long hose that had to be kept under a constant water mist to shield it against the fire's tremendous heat as the firefighters led the hose through to the shelters where the people were trapped. The reach of each of the little jets issuing from the holes in the hose overlapped each other, making a continuous, artificial "rain zone".
The bunkers were reached towards 7am Sunday morning, after the fire storm had reached its greatest intensity. All the trapped people were still alive, but had no idea what lay outside for them. All 23,000 managed to reach safer areas, such as the museum park. Only at the air shelter did help arrive too late: 95 of the 104 people inside had suffocated by the time the fire brigade reached them. The firestorm had been so intense in this particular part of the city that it had used up nearly all the oxygen, making saving more than 9 people impossible.
Effects.
A large part of 's tightly packed city centre was made up of about 800 timber-frame houses, many of which dated back to the Middle Ages. The city also