Defense of the Polish Post Office in Danzig The Defense of the Polish Post Office in Danzig ( Gdańsk ) was one of the first acts of World War II in Europe , as part of the Invasion of Poland . On September 1 , 1939 , Polish personnel defended the building for some 15 hours against assaults by the " SS Heimwehr Danzig " ( SS Danzig Home Defence ) , local SA formations and special units of " Ordnungspolizei " ( Danzig police ) . All but four of the defenders , who were able to escape from the building during the surrender , were unjustly sentenced to death by a German court martial as illegal combatant s on October 5 , 1939 and executed . Prelude . The Polish Post Office ( " Poczta Polska " ) in the Free City of Danzig was created in 1920 under the Treaty of Versailles , and its buildings were considered extraterritorial Polish property . The Polish Post Office in Danzig comprised several buildings . As tensions between Poland and Germany grew , in April 1939 the Polish High Command detached combat engineer and Army Reserve Sublieutenant ( or 2LT ) Konrad Guderski to the Baltic Sea coast . With Alfons Flisykowski and others , he helped organize the official and volunteer security staff at the Polish Post Office in Danzig , and prepared them for possible hostilities . In addition to training the staff , he prepared the defences in and around the building : nearby trees were removed and the entrance was fortified . In mid - August , ten additional employees were sent to the post office from Polish Post offices in Gdynia and Bydgoszcz ( mostly reserve non - commissioned officer s ) . In the Polish Post Office complex on 1 September 1939 there were 57 people : Konrad Guderski , 42 local Polish employees , 10 employees from Gdynia and Bydgoszcz , and the building keeper with his wife and 10 - year old daughter who lived in the complex . Polish employees had a cache of weapons , consisting of three Browning wz . 1928 light machine gun s , 40 other firearm s and three chests of hand grenade s . The Polish defence plan assigned the defenders the role of keeping Germans from the main building for 6 hours , when a relief force from Armia Pomorze was supposed to secure the area . The German attack plan , devised in July 1939 , determined that the main building and its defenders would be stormed from two directions . A diversionary attack was to be carried out at the front entrance , while the main force would break through the wall from the neighbouring Work Office and attack from the side . The battle . At 04 : 00 Germans cut the phone and electricity lines to the building . At 04 : 45 , just as the German battleship " Schleswig - Holstein " started shelling the nearby Polish Army military outpost at Westerplatte , German forces began their assault on the Polish Post . German units detached for this task were composed of the special unit of Danzig police , local SA formations and the SS units " SS Wachsturmbann " E " " and " SS Heimwehr Danzig " , supported by at least three ADGZ heavy armored cars . The attack was commanded by German police colonel , Willi Bethke . The first German attack , from the front , was repelled , although Germans managed to break through the entrance and briefly enter the building ( at the cost of two killed and seven wounded attackers , including one group leader ) . The second attack , from the Work Office , was also repelled . The commander of Polish defence , Konrad Guderski , died during that second attack from the blast of his own grenade which stopped the Germans who broke through the wall . At 11 : 00 German units were reinforced by the Wehrmacht with two 75 mm artillery pieces , but the second attack , even with the artillery support , was again repulsed . At 15 : 00 Germans declared a two hour ceasefire and demanded that Polish forces surrender , which they refused . In the meantime , Germans received additional reinforcements : a 105 mm artillery piece , and a unit of sappers , which dug under the walls and prepared a 600 kg explosive device . At 17 : 00 the bomb was set off , collapsing part of the wall , and German forces under the cover of three artillery pieces attacked again , this time capturing most of the building except the basement . At 18 : 00 Germans brought automatic pumps , gasoline tanks and flamethrower s , which they used to flood the basements with burning gasoline . After three Poles were burned alive ( bringing the total Polish casualties to six killed in action ) , the rest decided to capitulate . The first two people to leave the building — director Dr . Jan Michoń , carrying a white flag , and commandant ( " naczelnik " ) Józef Wąsik — were shot by the Germans ( according to one version , Dr . Michoń was attacked with a flamethrower ) . The rest of the Poles were allowed to surrender and leave the burning building . Six people managed to escape from the building , although two of them were captured the following days . Aftermath . 16 wounded prisoners were sent to the Gestapo hospital , where six subsequently died ( including the 10 - year old Erwina ) . The other 28 were first imprisoned in the police building and , after a few days , sent to Victoriaschule , where they were interrogated and tortured . Some 300 to 400 Polish citizens of Danzig were also held there . Court martial . All the prisoners were put on trial in front of the martial court of the Wehrmacht ' s Gruppe Eberhardt . A first group of 28 Victoriaschule - prisoners , with a single Wehrmacht officer as defence lawyer , was tried on 8 September , a second group of 10 , who recovered in the hospital , on 30 September . All were sentenced to death as illegal combatant s under the German special military penal law of 1938 . The sentence was demanded by the prosecutor Hans Giesecke and declared by presiding judge Kurt Bode , Vice - President of the Oberlandesgericht Danzig ( Higher Regional Court of Danzig ) . 28 of the judgements were countersigned , and thus became legally valid , by General Hans Günther von Kluge , the further 10 by Colonel Eduard Wagner , who committed suicide on 23 July 1944 as a member of the 20 July plot . A clemency appeal was rejected by General Walther von Brauchitsch . A similar fate awaited eleven Polish railway workers south of the city after they foiled a German attempt to use an armoured train , and were executed by the SA along with their immediate families . The prisoners were mostly executed by firing squad led by SS - " Sturmbannführer " Max Pauly ( later commandant of the Neuengamme concentration camp ) on 5 October and buried in a mass grave at the cemetery of Danzig - Saspe ( Zaspa ) . One , Leon Fuz , was later recognised and murdered in the Stutthof concentration camp in November . Four defenders who managed to escape and hide survived the war . Families of the postmen were also persecuted . Giesecke and Bode were never held responsible for this episode or held accountable for the judicial murder . They were denazified after the war and continued their careers as lawyers in Germany . Both died of natural causes in 1970s . Only in 1997 / 8 , the German court at Lübeck ( the Große Strafkammer IIb and the Dritte Große Strafkammer ) invalidated the 1939 Nazi sentence , citing among the reasons that the Special military penal law had only taken effect in Danzig on November 16 , 1939 and charged the presiding judge with neglience of his duties . The decision of the German court occurred thanks to the work of a German author , Dieter Schenk , who published a monograph on the defense of the post office and referred to the execution of the defenders as Judicial murder ( " Justizmord " ) . Schenk stresses the commanding role of Danzig policeforces , which made a Wehrmacht court martial not competent to convict the defenders . Instead , the Free City of Danzig ' s penal law would have been applicable , without the alternative of a death penalty . Cultural Legacy . In Poland , the whole episode has become one of the better known episodes of the Polish September Campaign and it is usually portrayed as a heroic story of David and Goliath proportions . In this view , it was a group of postmen who held out against German SS troops for almost an entire day . In 1979 in the People ' s Republic of Poland a Defenders of the Polish Post Monument was unveiled in Gdańsk . The Polish defense of the post office was also sympathetically portrayed in " The Tin Drum " by Günter Grass .