sentences:  Filipchenko was married to Nadezhda Pavlovna, with whom he had a son by the name of Gleb, who was a physicist.Both Nadezhda and Gleb were killed during the blockade of Leningrad in World War II.Filipchenko developed a severe headache whilst working at Peterhof, and concerned about his health, traveled to Leningrad to be taken care of by his brother Aleksandr.