Fans and fellow musicians continue to mourn the loss of Hawthorne Heights' guitarist Casey Calvert, who [article id="1574943"]passed away Saturday[/article] on the band's tour bus outside the 9:30 Club in Washington, D.C. The cause of the guitarist's death remains uncertain, and a spokesperson for the city's chief medical examiner's office told MTV News that the results of the guitarist's death might not be known for 90 days, pending the results of an autopsy that has already been completed.

News of Calvert's untimely death has been met with shock and sadness by his fans and his fellow musicians, who remember him as a kind and caring soul who loved to laugh and loved being in a band with his best friends.

"My mind was blown when we got the call about Casey passing away," Fall Out Boy bassist Pete Wentz wrote in an e-mail to MTV News on Monday. "It's something that hits you pretty hard, especially after we got to know Casey on the Black Clouds [and Underdogs] Tour. He was one of the sweetest guys in a band that we've ever had the chance to tour with. More than anything, it reminds you of what's really important in life — it humanizes the situation. Maybe gossip in blogs and first-week sales mean a bit less than telling people you care about how much you love them."

Wentz's FOB bandmate Joe Trohman also shared his thoughts with MTV News, saying, "I'm still in utter shock at the passing of Casey. It's really hard to believe that it happened, and so suddenly. We knew him and the rest of HH long, long ago back in our van days, and got even better acquainted when we did the Black Clouds and Underdogs Tour together in '06. He was a stand-up guy, real easy to hang with, and had a great heart. I know for a fact [this has] struck a chord with everyone we are currently on tour with and made us all realize our mortality. I couldn't imagine finding out one of my bandmates, one my brothers, had passed away. Especially while on the road. Our condolences and our hearts go out to the Calvert family and HH. We should all pay our respects by remembering the great guy Casey was, and the positive effect he had on those around him."

De'Mar Hamilton, drummer for the Plain White T's — who have been on tour with Hawthorne Heights multiple times — wrote this e-mail to MTV News on the band's behalf Tuesday (November 27): "Casey Calvert was a great person. He was the one in the group who I felt was the most entertaining. The last time we were on tour together was the Nintendo Fusion Tour. He was a Starbucks lover like me, so a couple times we would walk to get Starbucks together. What I remember most about him was that every night after they were done with their set, he would immediately change into his pajamas. I would call him out about it because it was so funny; it was like clockwork. Casey will be missed by all of us. It was very unfortunate what happened. He will be in our thoughts forever."

In another e-mail to MTV News on Tuesday, Relient K — who shared the stage with Hawthorne Heights on the 2006 Nintendo Fusion Tour — remembered Calvert as an "incredibly uplifting" person who touched many around him with his personality and his music. And frontman Matt Thiessen echoed the sentiments of many when he mentioned Calvert's infectious sense of humor.

"My favorite thing about Casey was his laugh," he wrote. "Whenever Casey and I hung out, he made me feel better about myself. I'm one of those guys that jokes around so much that my closest friends don't think I'm funny anymore. Casey laughed at 99 percent of my jokes, and his laughter was so great that it was contagious. I can guarantee that I'm not the only person who loved hanging out with Casey because of his lighthearted approach to life. As his bandmates said on their Web site, 'he was quirky and he was awesome,' and I'll miss him."

Philadelphia's the A.K.A.s, who were on the road with Hawthorne Heights when Calvert died, posted a lengthy MySpace bulletin about the guitarist, with lead singer Mike Ski writing that Calvert was "hilarious, funny, fun-loving, goofy and amazing ... With that in mind, I'm going to do my best to celebrate his memories with a smile rather than to dwell on the awful facts that he was too young, too awesome and too good of a person to live so short.

"I think anyone who knows him on any level, from very well to in passing would agree, this is the best way to remember him," Ski continued. "With that in mind, as I think of the last few things we said to each other, it makes me want to hold my friends closely and be thankful for the chance to make the most of this life. I urge everyone to do the same ... call someone you haven't spoken to in a while, appreciate the people you see every day but might take for granted at times, and do your best to live with passion for what you do."

Tributes to the late guitarist continued to fill both Hawthorne Heights' MySpace page and his personal page on Victory Records' "VictorMe" network, and fans have also expressed their sadness through MTV's You Tell Us, writing notes that offered condolences to Calvert's wife, a ninth- and 10th-grade English teacher in Oxford, Ohio, and remembered the guitarist as both a musical inspiration and a kind-hearted soul.

"Casey's wife Ashley was my teacher for 10th-grade English and she always had wonderful things to say about her husband that she loved so much," Stephen, a 16-year-old from Calvert's hometown of Hamilton, Ohio, wrote. "I just want to say that his family will be in my prayers, and I am so sorry for your loss."

"I am still in utter disbelief upon hearing of Casey's death. I have been a fan of HH since the very beginning and have watched these guys progress from nothing to one of the biggest bands on the charts," Brett, an 18-year-old from South Charleston, West Virginia, wrote. "It was only four weeks ago that I last saw Hawthorne Heights in Huntington, West Virginia. It was an amazing show ... I give my deepest sympathy to Hawthorne Heights. Hang in there guys, I have lost a bandmember myself and it is the hardest thing to live through, but it gets easier in time. Just keep on keeping on and doing what you do best and always play in Casey's memory."

"Casey was a huge inspiration to me, and if it wasn't for him, I would probably still live in a bubble. He is one of the main reasons I play guitar, and I will never forget him," another message read. "For the rest of you guys, I know this is hitting you so much harder than the rest of us, but please don't stop writing. I know it won't be the same, but this band means so much to me. I love you guys."