Ill-equipped, undermanned and lacking any anti-tank artillery, the Polish defenders relied mostly on improvised anti-tank defences, such as bottles of gasoline or turpentine and anti-tank obstacles. On September twenty the Soviet tanks reached the city's outskirts. After two days of heavy fights, often in close quarters, much of the city centre was destroyed by Soviet artillery. Seeing no chance for further defense, on September 22 the remainder of the Polish forces withdrew towards the Lithuanian border. General Olszyna-Wilczyński's car, in which he traveled with his family and adjutant captain Mieczysław Strzemeski were stopped by a tank-artillery group under command of Maj. Chuvakin on September 22 near Sopoćkinie. The general and his adjutant were shot after a brief interrogation, while his wife and driver were allowed to continue the journey.