The 200 million occasional inhabitants of Google Earth awoke to a new crisis in their virtual world: Darfur is burning, just like it is in reality.

Google on Tuesday added several new layers to Google Earth. These multimedia overlays, available upon opening the application, include Crisis in Darfur, a collection of maps, photos, and videos of the region's ongoing strife, assembled by the U.S. Holocaust Memorial Museum in collaboration with Amnesty International, Physicians for Human Rights, the U.S. State Department, and other international organizations; Trimble Outdoor Trips, a collection of U.S. hiking, biking, and climbing trails collected by Trimble and Backpacker magazine; and 100% Pure New Zealand, a geo-guide created by Tourism New Zealand, among others.

"At Google, we believe technology can be a catalyst for education and action," said Elliot Schrage, Google's VP of global communications and public affairs, in a statement. "Crisis in Darfur will enable Google Earth users to visualize and learn about the destruction in Darfur as never before and join the museum's efforts in responding to this continuing international catastrophe."

The Darfur layer, which resides in Google Earth's Global Awareness folder, is unique in that it's the only Global Awareness layer that's turned on by default.

Other layers documenting planetary problems in that folder -- the United Nations Environment Programme Atlas of Our Changing Environment, the World Wildlife Fund's Conservation Projects, Appalachian Mountaintop Removal, and Jane Goodall's Gombe Chimpanzee Blog -- are turned off by default.

"What makes this sort of unprecedented is there's no other place on Google Earth where something like this is highlighted," said John Heffernan, director of the Genocide Prevention Mapping Initiative at the U.S. Holocaust Memorial Museum. "If you fly over Africa, there's no way to avoid seeing Darfur."

Whether that's a problem for the Sudan and nations that support it, such as China, remains to be seen. But Google risks a possible backlash against its software if Google Earth mirrors the real world too closely, or not closely enough. Two weeks ago, for example, Congressman Brad Miller, D-N.C., wrote in a letter to Google CEO Eric Schmidt that it appeared Google was "airbrushing history" by reverting to satellite imagery of the Louisiana Gulf Coast that predated Hurricane Katrina.

Google didn't respond to a request to elaborate on its criteria for adding default data layers to Google Earth.

Heffernan said that his organization started a discussion with Google some 10 months ago and that Google came to the conclusion that it "needed to highlight this." The Darfur genocide has claimed 300,000 lives and left 2.5 million people homeless, according to Heffernan.

"Our main goal is to build a community of conscience that can be poised to respond to these crises," said Heffernan.

Looking ahead, Heffernan hopes Google will help his organization highlight not just ongoing crises, but potential genocides. "The idea is to prevent it before it happens," he said.

In conjunction with today's release, the U.S. Holocaust Memorial Museum also released a related map data layer of Holocaust sites and incidents, which can be downloaded from the organization's Web site.

Editor's note: This story was corrected on April 27 to remove the group Doctors Without Borders from the list of those who helped to create the Crisis in Darfur overlays and add the group Physicians for Human Rights to that list.