Former Rainbow and Dio bassist Jimmy Bain, who passed away Jan. 23 while on tour with Last in Line as part of Def Leppard's Hysteria on the High Seas Cruise, was suffering from undiagnosed lung cancer.

Bain's Last in Line bandmate Vinny Appice shared the news on the band's Facebook page, telling fans that although Bain was aware of — and receiving treatment for — a case of pneumonia at the time of his death, he didn't know he had lung cancer. "This didn't stop him or slow him down, we had four rehearsals four hours a day, then a flight to Miami for the Def Leppard Rock Cruise," wrote Appice. "A pre-sail gig and sound check was scheduled for the following day. At the gig Jimmy played great and even sang that night while holding a heavy bass guitar on his back, never complaining or asking for help."

Aside from a sobering reminder that aggressive early screenings can help identify conditions we might never otherwise know we have, the circumstances surrounding Bain's passing underline his love of and consistent commitment to his music and his bandmates. "Jimmy was a trooper, he gave his all to the band he loved, the music he loved and the fans," wrote Appice. "He didn't want to let anyone down. I don't know anyone that would have attempted this schedule while being this sick and not feeling well, a trooper."

The surviving members of Last in Line have since released a pair of tracks from their upcoming debut album, Heavy Crown, in tribute to Bain — an early taste of recordings that he, in Appice's words, was "so happy and proud" to have played on. "We were all looking forward to being on the road and playing together again, there was such a magic between us," added Appice. "Our prayers go out to his family and so many friends and fans who will miss the amazing person that was Jimmy Bain."

Top 10 Jimmy Bain Albums