Next to radio, SMS is one of the best ways to reach people in Haiti. So when it became clear that Tropical Storm Isaac was heading toward the small Caribbean island nation this past weekend, the Red Cross began sending out text messages.

Haiti is threatened by storm Isaac. Beware strong wind and rain, flooding, landslides. Stay vigilant, listen to the radio and call 733.

That’s an example of how the Red Cross used SMS to alert Haitians to the stormy weather brought on by Tropical Storm Isaac. It’s one of several text messages originally written in Créole sent out before and after the storm passed over Haiti. The messages were simple but effective: avoid flooded areas, mudslides and downed power lines, don’t drink flood water and use latrines, and call for more info.

Using SMS in Haiti Photo credit: IFRC

Here’s where we see the real power of using SMS in Haiti. Each text message reached 70,000 mobile subscribers and included a number to call for additional information. This phone line received more than 43,000 calls over the course of four days, clearly demonstrating that the messages reached the intended audience and helped people stay safe during the storm.

It’s not the first time the Red Cross has turned to mobile technology to share information in Haiti. During the cholera outbreak in 2010, the Red Cross used SMS to share information on how to treat the symptoms of cholera and prevent the spread of the disease.

Here’s an interesting case study from IFRC on the use of SMS by the Red Cross in Haiti since the 2010 earthquake.