Hawthorne Heights, with Casey Calvert at far right.

After spending more than a year battling its management and label, the members of Hawthorne Heights have a whole new level of turmoil to handle.

Hawthorne Heights guitarist Casey Calvert was found dead on the band's tour bus Saturday, hours before a scheduled show in Washington, DC. Calvert was 25.

The cause of death has yet to be determined, although in a post on its Web site, the band emphasized, "We can say with absolute certainty that he was not doing anything illegal."

Calvert reportedly used an inhaler for acute asthma and, pending toxicology results, this condition could have caused his death.

"Today is probably the worst day ever," band members Eron Bucciarelli, Micah Carli, Matt Ridenour, and JT Woodruff wrote. "It's with our deepest regrets that we have to write this. Casey Calvert passed away in his sleep last night. We found out this afternoon before sound-check. We've spent the entire day trying to come to grips with this and figure out as much as possible. At this time we're not sure what exactly happened. Just last night he was joking around with everyone before he went to bed."

The band asked fans not to contribute to any gossip about Calvert's death and to wait until a cause of death is determined.

"We don't want his memory to be tainted in the least," the band wrote. "Casey was our best friend. He was quirky and awesome and there will truly be no others like him!"

Hawthorne Heights was at the beginning of its "Wintour 07" and had played a show in Detroit Friday before arriving in DC for a show at the 9:30 Club.

The pop-punk band formed in 2001 in Dayton, Ohio, and has released two albums, the second of which entered the Billboard charts at No. 3.

Casey Calvert is survived by his wife, two stepsisters, and his mother and father.