The devastating earthquake in Haiti is the biggest natural disaster so far in the Twitter era, and response on the micro-blogging site has been accordingly momentous.
According to Twitter.com, four of the 10 most popular topics on the site were related to Haiti, where the death toll from a magnitude 7.0 earthquake on Tuesday could run into the tens of thousands.
Among them were the terms Port-au-Prince, Help Haiti, and Yele, a charity organization founded by Haitian-born musician and record producer Wyclef Jean.
Jean was asking people to text the word Yele to the number 501501, which will automatically charge the user's account $5 and donate the funds to the Yele Haiti Earthquake Fund.
WARRIORS HAITI NEEDS U NOW! Jean tweeted at one point. PLEASE LEND YOUR PRAYERS AND SUPPORT TO THE EARTHQUAKE RELIEF EFFORT TEXT 'YELE' TO 501 501 OR VISIT YELE.ORG.
Since its creation in 2006, privately owned San Francisco-based Twitter has become wildly popular as a social networking site and means of communicating information in 140-character bursts.
A search for the term Haiti on Twitter found it awash with other means to help, in several languages, including links to websites for such agencies as the Red Cross and Unicef.
Twitterers also shared news from the region, such as aftershocks rattling the Haitian capital, Port-au-Prince, or new reports of injuries or deaths.
Others took to the website to pour out their grief or anger. A user with the screen name Crys_Michelle said: R.I.P. to all involved with the Haiti disaster!!! Ssooo sad.
Nearly as popular were tweets on the site reacting to U.S. televangelist Pat Robertson, who told viewers of his Christian Broadcasting Network on Wednesday that Haiti had been cursed by an 1804 pact to the devil.
User michaelianblack wrote, What kind of deal with the devil did we make to deserve Pat Robertson?
(Editing by Ed Stoddard and Peter Cooney)