On Sunday Captain Sir Tom Moore, the World War II veteran who raised nearly £33 million (approximately $40 million) as a “thank you” to the frontline National Health Service staff battling COVID-19, was hospitalized with the virus and pneumonia, his daughter Hannah Ingram-Moore first shared via Twitter

Moore’s daughter said the WWII veteran had been treated for pneumonia over the past few weeks and tested positive for the virus last week.

After a short battle, his daughter confirmed on Tuesday that Moore passed away from COVID-19 complications.

With the initial goal of raising $1,250, which originally like “a stretch” to Moore’s daughter, the veteran’s fundraising efforts quickly went viral, with more than 1.5 million supporters donating to Moore’s cause to date.

The Army veteran quickly garnered national and international admiration by walking 100 laps of his garden — at 10-lap increments a day — in Bedfordshire, England prior to his 100th birthday during the first national lockdown.

For his fundraising efforts, Moore was named one of GQ’s “Men of the Year” and was knighted by the Queen in July.

On Sunday support for Moore has come pouring in, with Prime Minister Boris Johnson tweeting: “You’ve inspired the whole nation, and I know we are all wishing you a full recovery.”

“Let’s all carry on and remember that things will get better,” Moore previously told BBC News. “We have had problems before — we have overcome them — and we shall all overcome the same thing again.”

Story updated on February 2, 2021.