Markus Sandlund (search), 29, of the Stockholm Strings and Horns, performed on Wilson's Grammy-nominated "Smile" (search) album and Wilson's recent "Smile" tour. Sandlund and his girlfriend, Sophia, went to Thailand after finishing the "Smile" tour in Australia and New Zealand, according to a statement Wednesday on Wilson's Web site.
The couple, vacationing at the Orchid Beach Resort at Khao Lak (search), were in the hotel pool when the enormous wave hit. Sophia was swept away and later rescued, but Sandlund has not been found.
"I have been devastated since I heard the news that Markus is missing in Thailand," said Wilson, 62. The singer-songwriter said he has dispatched an "agent" to try to find the musician but has turned up no trace of him. He asked that anyone with any information contact his Web site.
"My prayers go out to all of the victims and their families and I would ask you to say a prayer for Markus' safe return," Wilson added.
Sandlund was one of 22 musicians and a dozen singers Wilson assembled to record "Smile," a 47-minute rock opera.