Relient K [ tickets ] frontman Matt Thiessen, whose band is nearing the end of its stint on the Winter Wonder Slam tour with Toby Mac, has pulled out of the run due to a family emergency.

"Due to circumstances beyond any of our control, Matthew Thiessen needed to leave the Winter Wonder Slam last evening on a red eye flight to Canton," the band's manager, Kevin Spellman, said in a prepared statement. "It is with great sadness to report that Matt’s mother suffered a severe heart attack Monday evening. Matt flew home to be with his family and at his mother's side as she undergoes quadruple bypass surgery. We truly appreciate your understanding and prayers during this highly emotional time."

Thiessen updated his Twitter feed last night (12/16) with a message that indicates his mother's surgery was a success.

"Pretty sure the Dr. fixed my mommy," he wrote. "My heart feels better now, too."

Thiessen's Relient K bandmates--Ethan Luck, John Warne and Jon Schneck--plan to remain on the road to finish out the last four shows on the Winter Wonder Slam run (shown at right), during which the trio will "play host to Tim Skipper of House of Heroes as they put together a medley of holiday music and fan favorites," according to Spellman's statement.

"As an effort to make the shows special, we will host a contest to have a fan club member join the guys on stage to perform 'Sadie Hawkins Dance,'" Spellman added.