Ivana Trump, the Czech American ex-wife of former President Donald Trump and mother of Ivanka, Eric and Don Jr., died Thursday. She was 73. Trump was discovered at the bottom of a staircase in her home on 10 E. 64th St. in Manhattan at 12:40 p.m., police sources told The Post. Authorities believe she suffered a cardiac arrest, but the official cause of death has yet to be determined. She was found by cops who were called to her home for a wellness check, police said.