David Cook's Brother, Adam passes away after long battle with cancer.

He was a valiant fighter. RIP..........

After a long and valiant struggle with brain cancer, “American Idol” winner David Cook’s brother Adam died at 1 a.m. this morning at a hospice in Terre Haute, IN.

A family friend told RadarOnline.com exclusively, “Adam passed away peacefully.

“He was surrounded by his family, including his wife Kendra, his children, his father and his step-mom, among others.”

David was rushing back on a jet when his beloved brother died.

“The family thought that Adam would go much sooner than this, actually,” said the Cook family friend.

“That’s why David left his tour a few weeks back so that he could be with Adam.

“They said their goodbyes then.”

But Adam, 36, rallied briefly after that…and David returned to his concert tour.

“He took a turn for the worse this weekend and David rushed to get home.”

But sadly he couldn’t make it in time.

Last year, friends of the stricken lawyer arranged a $45,000 trip on a chartered medical jet to Los Angeles so Adam could see David perform on Idol.