Ryan Dunn. (Jim Ruymen/Reuters)

Johnny Knoxville, who performed outrageous yet hilarious stunts with Dunn on MTV’s “Jackass,” posted a picture of the late stuntman and prankster on Twitter with the message, “Today I lost my brother Ryan Dunn. My heart goes out to his family and his beloved Angie. RIP Ryan, I love you buddy.”

The usually gregarious Steve-O tweeted, “I don’t know what to say, except I love Ryan Dunn and I’m really going to miss him.”

Jason “Wee-Man” Acuna, a member of the rowdy MTV crew, remembered Dunn on Twitter: “I MISS YOU BUD!! You were always a happy kick-[butt] dude!!” Snowboarder and stunt performer Dave England simply tweeted, “I love you Ryan. I'm gonna miss you bad.”

Dunn’s longtime friend and “Viva La Bam” cohort Bam Margera has yet to publicly respond. April Margera, Bam’s mother, confirmed the news this morning on the “Preston and Steve” radio show, telling news outlets, including Radar Online, “I felt like I lost on of my own sons.” She told MyFoxPhilly.com that her son is “devastated” by the loss.

Dunn and an unidentified passenger were killed early Monday morning in a fiery crash off Route 322 in Pennsylvania. The cause of the accident has not been made public.

Jessica Chobot, who co-hosted the new G4 show “Proving Ground” with Dunn, said in a tweet, “Ryan was a wonderful friend, co-host and a brilliant man. My heart hurts for his family & friends and I will miss him greatly.”

A seemingly random assortment of celebrities — from Tom Green to Sofia Coppola — have remembered Dunn on Twitter. Read their tweets below.

We’re deeply saddened by the passing of a member of the MTV family, Ryan Dunn. Our hearts and thoughts are with his friends and family.less than a minute ago via web Favorite Retweet ReplyMTV
MTV

Today I lost my brother Ryan Dunn. My heart goes out to his family and his beloved Angie. RIP Ryan , I love you buddy. http://say.ly/hUnqQQless than a minute ago via WhoSay Favorite Retweet ReplyJohnny Knoxville
realjknoxville

RYAN DUNN-- a super awesome memory was at the J RODY walston & the business show!!! I MISS YOU BUD!! You were alway... http://say.ly/zISqQ7less than a minute ago via WhoSay Favorite Retweet ReplyJason Weeman Acuna
iamweeman

G4 is shocked and saddened by the tragic news that Ryan Dunn has passed away. We extend our heartfelt condolences to his family and friends.less than a minute ago via HootSuite Favorite Retweet ReplyG4TV
g4tv

Just heard that Ryan Dunn from Jackass died last night in a car wreck. Rest In Peace Ryan.less than a minute ago via Twitter for iPad Favorite Retweet ReplyTom Green
tomgreenlive

RIP ryan dunn. You were an amazing guy and you were cut way to short. Enjoyed the times we had. My heart goes out to his family and friendsless than a minute ago via Twitter for BlackBerry® Favorite Retweet ReplyCarey Hart
hartluck

Ryan Dunn has passed away, he was a very nice and energetic guy, I met him a couple of times. Very shocked.less than a minute ago via Twitter for iPhone Favorite Retweet ReplySofia Coppola
msSofiaCoppola

I’m very Sad and Shocked to hear about Ryan Dunn. My thoughts&Prayers are with his Family.less than a minute ago via Twitter for iPhone Favorite Retweet Replybenji madden
benjaminmadden

so sad to hear about Ryan Dunn... and in is honor I say this: I am mad AND disappointed...#RyanDunnless than a minute ago via web Favorite Retweet ReplyColin Hanks
Colin_Hanks

Rest in peace. Ryan Dunn, star of the “Jackass” TV show/movies, has died in a car crash: http://apne.ws/jt1EE3 /via @APless than a minute ago via Twittelator Favorite Retweet ReplyAlyssa Milano
Alyssa_Milano

R.I.P. Ryan Dunn. A truly BRILLIANT physical performer. ...Gone too soon...less than a minute ago via Mobile Web Favorite Retweet ReplyJackée Harry
JackeeHarry