Mondrian's last painting, Victory Boogie-Woogie, which he began in 1943, sadly remained unfinished at the time of the artist's death on February 1, 1944, from pneumonia. The painter's sole heir was the young artist Harry Holtzman. During the German Blitz of London in 1940, Holtzman had arranged for Mondrian to come to New York. Holtzman rented an apartment-studio for him, and during the next three and a half years he was one of Mondrian’s most intimate associates.