New Delhi, May 24 -- Doug McCain, a Navy pilot and the eldest child of US Senator John McCain, has died suddenly at the age of 66, his family announced.

His sister, Meghan McCain, shared the news in an emotional public tribute, remembering her brother as a joyful and supportive presence in her life.

"I am deeply saddened to share the news of my brother Doug McCain's sudden passing. He was a truly wonderful, joyful man who supported me throughout my life. He brought humor, fun and great conversation to every room. I will cherish our memories together. Our prayers are with his wife Ashley and children Caroline and Shepp," Meghan McCain said.

The cause of death was not immediately disclosed.

Doug McCain is survived by his wife Ashley, hi...