World Mounts Massive Relief Effort
 for Haiti

The United States and various aid groups from around the world have begun the massive relief effort to help Haiti after an earthquake left tens of thousands of people dead and injured, millions in need of emergency aid, and the nation's capital building in ruins.

President Barack Obama, facing the first large-scale humanitarian crisis of his presidency, pledged that the Caribbean nation will have the "unwavering support" of the United States.

U.S. Secretary of State Hillary Clinton said major damage to Haiti's main airport and ports had slowed down relief efforts. "There are about 3 million people affected. Thousands and thousands – I don’t want to put a number, but tens of thousands we fear are dead, many thousands more are injured," she said.

Clinton cancelled her visit to Australia to help organize the relief effort with various members of the Senate and military officials.

The first U.S. Army troops were heading to Haiti Thursday and the first group of soldiers from the 82nd Airborne Division will leave late Thursday, the Army said. The 100 troops will find locations to set up tents in preparation for the arrival of another roughly 800 personnel from the division on Friday.

Army personnel come on top of 2,200 Marines, also to be sent, as the military prepares to help with search and rescue, the delivery of humanitarian supplies and security needs. U.S. military officials also said more than a half dozen ships also are expected to help, with the largest, the aircraft carrier USS Carl Vinson, arriving Thursday.

The United Nations released $10 million from its emergency funds, even as U.N. forces in Haiti struggled with their own losses. The U.N. headquarters building collapsed, and at least 16 personnel are confirmed dead, with up to 150 still missing, including mission head Hedi Annabi of Tunisia and his chief deputy, Brazilian Luis Carlos da Costa.

"We'll be using whatever roads are passable to get aid to Port-au-Prince, and if possible we'll bring helicopters in," said Emilia Casella, a spokeswoman for the U.N. food agency in Geneva.

An Air China plane carrying a Chinese search-and-rescue team left for Haiti Thursday. Medics and aid landed at Port-au-Prince airport early in the morning, and more than 50 workers in orange jumpsuits accompanied by trained sniffer dogs were on foot on the island by midday.

A British flight carrying a team of 71 rescue specialists along with heavy equipment arrived in the Dominican Republic Thursday, with the crew prepared to head to Haiti.

Other nations -- from Venezuela to Iceland – confirmed they would start sending aid workers and rescue teams. Cuban officials said its existing field hospitals in Haiti had already treated hundreds of victims.

France sent 65 rubble-clearing specialists and six sniffer dogs for Haiti, while Spain was rushing three airplanes with rescuers and 100 tons of tents, blankets and cooking kits.

"The population in Port-au-Prince and other earthquake-affected areas has spent a second night in the open. Frantic search and rescue activities have been continuing as international relief operations grind into action,'' the International Committee of the Red Cross wrote in a situation report on Thursday morning. "Efforts to assess the extent of this huge disaster are ongoing. While no accurate figures are yet available, the number of dead and injured is expected to be in the thousands, and as many as three million people appear to have been affected in one way or another."

Haitians are frantically struggling to save those injured by turning pickup trucks into ambulances and doors into stretchers, while hoping foreign governments will quickly send in aid.

All three hospitals operated by Doctors Without Borders collapsed in the quake or were abandoned due to infrastructure issues. Many of its doctors are missing.

The strongest standing hospital in the country is St. Damien, near the Port-au-Prince airport and the U.S. embassy. It reportedly has cracks in the walls but is fully functional.

The total number of dead bodies is expected to pose a problem. The World Health Organization said it has sent specialists to help clear Port-au-Prince of corpses and prevent the spread of disease, and the Red Cross was sending a plane Thursday, filled with body bags.