Fritz Stern, prominent historian and academic, dead at 90

NEW YORK (AP) — Fritz Stern, a refugee from Nazi Germany who became a prominent historian, government adviser and a longtime professor at Columbia University, has died.

In 1993, he took a leave absence from Columbia after being appointed a senior aide to his friend Richard Holbrooke, the U.S. ambassador to Germany.

"Fritz Stern rightly demanded of us Germans that the crimes against the Jews be preserved in our collective memory, to honor the victims, to learn from this rupture of civilization, and to develop standards for shaping the present," Gauck wrote.

Earlier this year, he told The History News Network that presumptive Republican presidential nominee Donald Trump was a symptom of the "dumbing down of the country."