Bombing of Helsinki in World War II

The capital of Finland, Helsinki was bombed several times during World War II. Between 1939–1945 Finland fought three wars, two against the Soviet Union and one against Germany. The largest raids were three raids in February 1944, which have been called The Great Raids Against Helsinki.

Helsinki's air defense
In the autumn of 1939, Helsinki was protected by the 1st Anti Aircraft Regiment consisting of four heavy anti-aircraft batteries of three to four guns each, one light AA battery and one AA machine gun company. The air defense of Helsinki was significantly strengthened from spring 1943 onwards under the lead of Colonel Pekka Jokipaltio. During the Continuation War Germany provided two early warning radars and four gun laying radars to Helsinki, further, 18 very effective German heavy 88 mm AA guns were also placed in Helsinki. The new six-gun batteries were grouped at Lauttasaari, Käpylä and in Santahamina. By February 1944 Helsinki was protected by 13 light and heavy AA-batteries. Air defenses included 77 heavy AA-guns, 41 light AA-guns, 36 search lights, 13 acoustic locators and 6 radars in addition to visual spotters and the Finnish Navy's anti-aircraft. Germany also provided some night fighter support against the Soviet attacks.

The air defense command system was based on the German system and was quite effective – key personnel had trained in Germany. Due to manpower shortages, the air defense also used 16-year-old boy volunteers from Suojeluskunta to man the guns and young girls of the Lotta Svärd organization to man search lights.

The Germans had also based a night fighter unit, consisting of 12 Bf 109G-6 nightfighters in Helsinki on 12 February 1944 and the German night fighter direction vessel Togo cruised in the Gulf of Finland between Tallinn and Helsinki.

Helsinki's air defenses prioritized stopping bombs from reaching the city over the destruction of air targets. In a special type of barrage, several batteries would fire a wall of flak in front of the approaching bombers in an attempt to scare them into dropping their payloads too early and breaking away. AA shells had been jury-rigged by drilling the fuze-hole larger and filling the extra space with magnesium mixed with aluminium, turning their explosion from a dull red to a searing white.

The Soviet long distance bomb group (ADD)
The bombing of Finland was generally conducted by the long-range bombing and reconnaissance group of the Soviet Air Force (VVS), the Aviatsiya Dalnego Deystviya (ADD). This group was directly subordinated to the Soviet High Command. During the February bombings of 1944 the ADD was reinforced with other units. The ADD commander was Marshal Aleksandr Golovanov. Bombing raids were also sometimes done by the VVS and the BF (Baltic Fleet air group).

The Soviet bomber fleet was very diverse. The majority of the aircraft were twin-engined Ilyushin-4, Lisunov Li-2, North American B-25 Mitchell and Douglas A-20 bombers. The B-25s and the A-20s had been supplied to the Soviet Union as Lend Lease materiel from the United States. The Lisunov Li-2 was a Soviet bomber version of the American Douglas DC-3. There were also some heavy four-engined bombers participating in the bombings, e.g. the Petlyakov Pe-8.

Civil defense
Before the war, Helsinki had quite an extensive civil defense system. By a city decree of 1934, shelters were constructed in all high-rise building basements. These were merely basement rooms with reinforced walls in order to withstand nearby bomb impacts. All buildings were required to have an appointed civil protection supervisor who was not in the reserves or the armed forces, and as such was usually unfit for military service. This person was tasked to see that all occupants made it to the shelter in an orderly fashion.

There were a few larger shelters built into solid rock, but it was not possible to fit all the citizens of Helsinki into these. Some hospitals were also equipped with subterranean shelters where patients could be relocated during air raids. Others, such as the Children's hospital, were moved outside the city. One hospital was entirely underground, below the Finnish Red Cross building.

Winter War
Three hours after Soviet forces had crossed the border and started the Winter War, Soviet planes bombed Helsinki. The most intensive bombing raids were during the first few days.

Helsinki was bombed a total of eight times during the Winter War. Some 350 bombs fell on the city, resulting in the deaths of 97 people and the wounding of 260. In all, 55 buildings were destroyed.

The Soviet bombings led to harsh reactions abroad. U.S. President Roosevelt asked the Soviets not to bomb Finnish cities. Molotov replied to Roosevelt: "Soviet aircraft have not been bombing cities, but airfields, you can't see that from 8,000 kilometers away in America."

Continuation War
Helsinki fared somewhat easier during the Continuation War since Soviet bombers mainly focused on German forces in the Baltic states. Helsinki was bombed 39 times during the Continuation War. 245 people were killed and 646 wounded, the majority in the three big raids of 1944.

The great raids of February 1944
In February 1944, the Soviet Union launched three massive bombing raids against Helsinki. The aim was to break the Finnish fighting spirit and force the Finns to the peace table. The raids were conducted on the nights of 6–7, 16-17 and 26-27 February. Joseph Stalin had obtained British and American support for this measure at the Tehran conference in 1943. In this manner the USSR hoped to force Finland to break its ties with Germany and agree to a peace settlement.

Finnish air defense forces counted 2,121 bombers in the three raids of February 1944, which dropped more than 16,000 bombs. Of the 34,200 shots fired against the bombers, 21,200 were with heavy AA artillery, and 12,900 were with light AA artillery. The Finns deceived Soviet pathfinders by lighting fires on the islands outside the city, and only using the searchlights east of the city, thereby leading the pathfinders to believe that it was the city. Only 530 bombs fell within the city itself. The majority of the population of Helsinki had left the city, and the casualties were quite low compared to other cities bombed during the war.

Of the 22-25 Soviet bombers lost in the raids, 18-21 were destroyed by AA fire, and four were shot down by German night fighters.

The first great raid: 6–7 February
The first night saw the most destruction.

The first bombs fell at 19:23. Some 350 bombs fell within the city and approximately 2,500 bombs outside Helsinki. The total amount of bombs dropped (included the ones that fell into the sea) amounted to some 6,990. Approximately 730 bomber aircraft participated in the raid. The bombers arrived in two waves: 18:51–21:40 on 6 February, and 00:57–04:57 on 7 February.

The defense fired 122 barrages. The light AA artillery fired 2,745 shots and the heavy AA artillery fired 7,719 shots. The Finnish Air Force had no night fighters at this time.

100 persons were killed, and 300 injured. More than 160 buildings were damaged. The AA defenses had issued some false alarms the previous days which had lowered people's readiness levels.

The second great raid: 16–17 February
Since Tallinn had been bombed heavily and intelligence pointed out that a raid might be directed at Helsinki, the Helsinki air defense took some active measures.

After the first raid, a German night fighter group of 12 Messerschmitt Bf 109G-6 fighters with special night fighting equipment was transferred to the Helsinki-Malmi Airport from the Estonian front. These managed to shoot down six bombers during the following two raids. The anti-aircraft batteries fired 184 barrages and downed two bombers. Heavy AA batteries fired 12,238 shots and light AA batteries fired 5,709 shots.

Most of the population of Helsinki had voluntarily evacuated to the countryside and the remainder were prepared to take shelter at first warning. This reduced casualties significantly.

This time 383 bombers participated. While 4,317 bombs fell on the city, the sea and in the surrounding area, only 100 bombs fell within the city. The warning was sounded at 20:12 and the bombers approached again in two waves: 20:12–23:10 on 16 February and 23:45-05:49 on 17 February. The first wave tried to concentrate the bombing by approaching from different directions. In the second wave, the aircraft came in smaller groups from the east. Finnish intelligence had intercepted messages one hour and 40 minutes before the raid and warned the air defense, which had time to prepare. The air defense sounded the warning 49 minutes before the raid. Radar picked up the first aircraft 34 minutes before the beginning of the bombings.

This time casualty figures were much lower: 25 died and 29 were injured. 27 buildings were destroyed and 53 were damaged.

The third great raid: 26–27 February
On the evening of 26 February, a single Soviet reconnaissance aircraft was spotted over the city. It was a sign of the coming attack. The weather was clear, which helped the attackers. Again Finnish Radio Intelligence intercepted messages of the forthcoming raid, this time 1 hour and 28 minutes before the bombing would commence - although the Soviets tried to maintain radio silence.

Five minutes later, the air surveillance grid, manned by Lotta Svärd auxiliaries, reported approaching bombers. A silent alarm was sounded in the city in good time before the raid. Street lights were turned off, trams and trains were stopped and radio transmissions ended. In this manner, the enemy had more difficulty finding their target. All citizens knew that they had to take cover.

The first bombers were picked up by Finnish radar at approximately 18:30, 25 minutes before they would arrive. A few minutes later, the night fighters took off and flew to their predesignated positions. The AA-artillery had also been alarmed. The air raid warning was sounded at 18:45. AA-batteries opened up fire at 18:53. At 19:07 the first bombs fell.

This last great raid differed from the two previous ones. The battle lasted for some 11 hours and was divided into three different phases. The first one was in the evening and lasted for four hours and concentrated the attacks against the city. The second one was mainly focused on the defending AA artillery, but to little success. The last wave hoped to finally flatten the city, but the majority of the aircraft turned away when met with fierce anti-aircraft barrages and night fighters. The all clear signal was finally sounded at about 6:30 in the morning of 27 February.

Despite that this had been the most massive raid, the damages were again quite limited: 21 people were killed and 35 wounded; 59 buildings were destroyed and 135 damaged.

The heavy AA artillery fired 14,240 shots and the light AA artillery 4,432 shots. Nine Soviet bombers were downed.

This time 896 bombers participated in the raid on Helsinki. They dropped 5,182 bombs of which only 290 fell on the city itself.

The damage of the great raids
Thanks to the efficiency of the anti-aircraft and deception measures, damage was limited. Only 5% of the bombs fell within the city, and some of these fell in uninhabited park areas causing no damage. Some 2,000 bombers participated in the three great raids on Helsinki and dropped some 2,600 tons of bombs. Of the 146 who died, six were soldiers; 356 were wounded. 109 buildings were destroyed. 300 were damaged by shrapnel and 111 were set on fire. The Soviets lost 25 aircraft.

By comparison, Dresden was bombed on 13–15 February 1945 by 1,320 bombers, which dropped 3,900 tons of bombs. This force was comparable to the total that attacked Helsinki, but the Dresden raid killed about 25,000 to 35,000 people and the city was almost completely destroyed.

After the war, the Allied Control Commission led by Soviet General Andrei Zhdanov came to in Helsinki. Zhdanov was perplexed by the limited damage the city had sustained. The Soviet leadership thought that they had destroyed the city completely and that it was these bombings that had forced the Finns to the peace table.

Finnish response
The Finnish Air Force responded to the air raids with series of night infiltration bombings of ADD airfields near to Leningrad. Finnish bombers - Junkers Ju 88s, Bristol Blenheims, and Dornier Do 17s - either tailed or in some cases even joined formation with returning Soviet bombers over the Gulf of Finland and followed these to their bases. Once most Soviet bombers had landed the Finnish bombers approached to bomb both the landed and still landing Soviet bombers and then escaped in the ensuing confusion. The first major night infiltration bombing took place on 9 March 1944 and they lasted until May 1944. However Soviet casualties from these raids could not be estimated reliably.