While touring the Center for Disease Control and Prevention’s headquarters in Atlanta in early March, President Donald Trump said he didn’t know anyone who had died of influenza. According to Trump biographer Gwenda Blair, his grandfather died of the flu during the 1918 influenza pandemic.

“When I was hearing the amount of people that died with the flu, I was shocked to hear it,” Trump said. “Over the last, long period of time when people have the flu, you have an average of 36,000 people dying. I’ve never heard those numbers, I would’ve been shocked. I would have said, ‘Does anybody die of the flu?’ I didn’t know people died from the flu.”

There were more than 34,000 deaths from the flu in 2018-2019, according to estimates from the CDC. The year prior, there were approximately 61,000. Preliminary estimates from this year range between 24,000 to 62,000.

According to the CDC, a worldwide influenza pandemic in 1918 killed an estimated 50 million people, 675,000 of which were in the U.S.

Blair’s biography, The Trumps: Three Generations of Builders and a President, which was based on interviews with the Trump family asserted that the president’s paternal grandfather, Freidrich Trump, died during the 1918 influenza pandemic.

“When I interviewed him for my book, he was not very interested in history in general — family history,” Blair said during an interview with CNN. “He was interested in his own business career, that was 100% of his interests at the time I interviewed him. But he knew generally about his father, grandfather and his grandmother, who was a widow after her husband died in 1918.”

She continued, “His grandmother, also a German immigrant, lived until the 1960s, across the street from the Trump family during much of Donald Trump’s childhood and was around until he was in college and was very close to his father. So his grandmother was around. I mean not just around … actively involved in the family.”

According to the book, Friedrich was a 49-year old businessman with three kids when he passed away.

Asked if it is possible Trump was unaware of his grandfather’s cause of death, Blair replied that it is “within the realm of possibility, sure [but] within the realm of probability, no.”

CORONAVIRUS FAQ: WIKI OF MOST FREQUENTLY ASKED QUESTIONS