Polish Defensive War: Facts

the main force of the Łódź Army was destroyed in the Battle of the Border during the Polish Defensive War of 1939, but an Operational Group held out for a month defending the Modlin fortress?
Józef Olszyna-Wilczyński was a high-ranking commander of the Polish Army, a veteran of World War I, Polish-Ukrainian War and the Polish-Soviet War, and was executed by the Soviets during the Polish Defensive War of 1939?