Hogg joined her elder brother William on a vacation in Germany in 1930. During their visit, he suffered a gallbladder attack and died on September 12, 1930 after emergency surgery. Ima brought her brother's body back to the United States. His will bequeathed $2.5 million to UT; his desire was that it be used alongside money donated by his sister for "far-reaching benefit to the people of Texas". Legal challenges tied up the grant until 1939, when the university received $1.8 million. In 1940, after discussion with her brother Michael—the executor of the will—Hogg used the money to establish the Hogg Foundation for Mental Health at the University of Texas at Austin.