Jack Martin — father of the late Joey + Rory singer Joey Feek and grandfather to 7-year-old Indiana Feek — has died. Rory Feek shared the news on his website, poetically paying tribute to his father-in-law of 20 years.

"On Sunday [March 21], my wife Joey got to see her daddy for the first time in five years. On her side of heaven," Rory writes to begin his post. Jack Martin was 73 years old and on a flight to Las Vegas, Nev., when he suffered a heart attack. The plane was diverted to Kansas City, but medical personnel could not revive him.

Joey's older sister, Jody, called Rory to tell him the news. She was inconsolable, he says.

"It was Jody who, five years ago, had taken off work for five months to help care for Joey as she passed. And now this," the songwriter and author writes. "Sometimes it feels unfair, like too much for one family to bear."

Martin will be buried next to his son Justin, who died in a car accident in 1994. Joey is buried at the Feek family farm in Tennessee.

"I haven't told Indiana yet," Rory shares. "I will, when we get up there and she can see and better understand what's happening, but right now it would probably be confusing for her. Too much for a 7-year-old who can't understand why her Mama can't FaceTime her on her birthday to take in at once."

Joey Feek died at age 40 in March of 2016 after a cancer battle, leaving behind Rory and their then-2-year-old daughter Indy. The heartbreaking story played out through Rory's blog over several months, with each honest update coming with heavy emotion and candor. The 55-year-old has never shied away from talking about his journey, later writing a memoir called This Life I Live in which he details everything that's happened in his life.

With a new album slated for June, Feek wonders in the words of his newest post about his own mortality and his preparedness for it.

It's a strange thing to think about waking up to what would feel like any other day, doing what you do... making coffee, showering, dressing, getting your day started like every other day. Only on that day, it wasn't going to be like the others. It was gonna be the last day. Dad was 73 years old. Doing some quick math, that's approximately 27,000 days of opening your eyes and waking and living and doing what you do. And then one day you don't.

I can't help but wonder when my last day might be. And if I'm prepared. If my children are. Are any of us really ready when it's our time?

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