Glee star Lea Michele Tweeted, "So devastating to hear about the huge earthquake & tsunami [in] Japan. My thoughts and prayers are with everyone there."
Her costar Amber Riley also spoke up: "Omg my heart goes out to Japan," she Tweeted. "I pray this devastation stops."
Lindsay Lohan, just a week away from the next step in her theft case, Tweeted a picture of her TV screen, set to CNN.
"My mommy just woke my sister and i [sic] up to this!" she said. "god [sic] bless those that are in fear."
Paris Hilton also seemed to be taken aback by the images of houses reduced to wreckage and farmlands flooded in northern Japan.
"The images on the news are breaking my heart," Hilton said on Twitter. "I am so worried for everyone in Japan. My thoughts are with you Japan. God bless you all."
A Trending TopicBy Friday morning, topics like #prayforjapan, #tsuanami and Godzilla were trending on Twitter, and Piers Morgan signed off his Tweets with a hashtag of his own: #prayforthem. "Desperate scenes on #cnn live from Japan," Morgan, who took over Larry King's time slot on CNN, Tweeted. "Can't remember ever watching such horrific natural disaster in real time like this. #prayforthem."
Celebs like Alyssa Milano, who is expecting her first child in the fall, used her Twitter feed to give her followers a play-by-play as news breaks in Japan.
Even the president took to the social media site to blast his message.
"Sending condolences to the people of Japan, particularly those who lost loved ones in the earthquake & tsunamis," President Barack Obama, a Honolulu, Hawaii native, said on Twitter. "U.S. stands ready to help."