PORT-AU-PRINCE, Haiti — Roads full of hungry, homeless people. A ruined port and an overwhelmed airport. Hundreds of crumpled buildings and little heavy machinery. Few working phones.
Relief supplies and emergency experts started pouring into Haiti from around the world Thursday but aid groups said the challenge of helping Haiti's desperate quake survivors was enormous.
"It's chaos," U.N. humanitarian spokeswoman Elisabeth Byrs told The Associated Press. "It's a logistical nightmare."
Aid deliveries by ship were impossible to Port-au-Prince because the Haitian capital's port was severely damaged by Tuesday magnitude-7 earthquake.
Fearful of going near quake-damaged buildings, Haitians stood or rested on the roads, slowing the transport of food and other crucial aid.
Severe damage to at least eight Port-au-Prince hospitals made it nearly impossible to treat the thousands of injured or prevent outbreaks of disease, said Paul Garwood, spokesman for the World Health Organization.
'The rest is dust'
Haiti, the poorest country in the Western Hemisphere, presents unique logistical challenges for aid workers even in the best of times. It shares an island with the Dominican Republic, meaning that aid must arrive by sea or air. Haitian streets are in poor condition under normal circumstances, and even if aid reaches the Dominican Republic, the road from there to Port-au-Prince is narrow and easily clogged.
Almost everything has to be imported, even wood for building temporary shelters, because Haitians have denuded their hillsides by cutting trees for cooking fuel.
"If you see Dominican Republic and Haiti from the air, it's really striking," said Byrs. "Half of the island is green and the rest is dust."
In addition, Haiti was already heavily damaged by a series of severe hurricanes, the most recent in 2008.
President Barack Obama announced Thursday the U.S. government was making an initial $100 million relief effort and promised an all-out rescue and humanitarian effort that included military and civilian emergency teams from across the U.S.
"We have to be there for them in their hour of need," Obama said.
At the same time, officials close to former President George W. Bush said that he and former President Bill Clinton, who is already a United Nations special envoy for Haiti, had agreed to help the quake relief effort.
One source familiar with the situation said Obama had talked by phone with Bush on Wednesday night about helping out.
Clinton and Bush's father, former President George H.W. Bush, joined in a huge international relief effort to help the recovery from the 2004 tsunami that swept South Asia and killed 226,000 in 13 countries after an earthquake in Indonesia.
The aircraft carrier USS Carl Vinson was deployed to Haiti, and the amphibious assault ship USS Bataan had been ordered to sail as soon as possible with a 2,000-member Marine unit.
Even as the United Nations stepped up its massive aid operation, the world body was trying to determine how many of its own staff were killed in earthquake.
"It's very difficult to give an exact number," said Byrs. "This is also a tragedy for the United Nations."
She said up to 100 U.N. staff were trapped in the main U.N. peacekeepers' building, which was destroyed.
Byrs said 40 search-and-rescue teams from around the world had started arriving in Haiti to look for survivors trapped inside collapsed buildings. But to find and save people, the rescuers need heavy machinery to lift tons of rubble — equipment that teams from places like Britain and Iceland have, but others don't.
Haiti has virtually none of those machines but aid workers were trying to get some into Haiti from the Dominican Republic, Charles Vincent of the World Food Program said.
"We'll have to see how that works out," said Vincent. "The U.S. military will also be bringing in some equipment."
The desperate situation has aid groups fearing a surge in lawlessness, Vincent said. U.N. peacekeepers are patrolling to try to control looting but they are dealing with many deaths and injuries of their own, he added.
The International Committee of the Red Cross said its forensic specialists would help ensure that bodies of the quake victims are recovered and identified for the benefit of their families.
The Red Cross set up a special Web site to help Haitians find their missing loved ones, and after just a few hours, over 5,000 people had already registered on it, many from the United States and Canada.
Aid was delivered or promised from many countries, including Brazil, the European Union, Britain, Germany, Israel, France, Switzerland, South Korea and Canada. China dispatched a chartered plane carrying 10 tons of tents, food, medical equipment and sniffer dogs, along with a 60-member earthquake relief team who worked in China's own 2008 earthquake, which killed some 90,000 people.
The Red Cross estimated that some 3 million people in Haiti will require aid, ranging from shelter to food and clean water, and said many Haitians could need relief aid for a full year.
Aid workers base such estimates on previous disasters that appear to be the same size, said Pablo Medina, operations coordinator of the International Federation of Red Cross and Red Crescent Societies.
"At this very early hour, with such limited amount of information, what you have to do is base your calls on past experience on previous earthquakes, on media reports and on information on the ground," Medina told the AP.
Initial planning is conservative and is normally revised upward as more information becomes available. This time, the Red Cross decided to send 100 experts to Haiti.
"That's fairly big," Medina said.
In an appearance on NBC's TODAY show, Secretary of State Hillary Clinton pledged long-term assistance to help Haiti recover from this week's devastating earthquake.
Video: Bill Clinton: ‘Before this, Haiti was making progress’ "This is going to be a long-term effort. We have the immediate crisis of trying to save those lives that can be saved, to deal with the injured ... to try to provide food, water, medical supplies, some semblance of shelter," Clinton said.
She said the U.S. government was also prepared to work with the Haitian government and other international partners to begin rebuilding the stricken country.
"This calamity has affected 3 million people. It has caused the collapse of ten of thousands of buildings. We know that there will be tens of thousands of casualties," Clinton added without providing specific numbers on fatalities.
Clinton said a 7,000-strong U.N. peacekeeping force was helping to maintain order and would receive help controlling looting and other violence from the U.S. Army's 82nd Airborne Division later on Thursday.
"The peacekeeping force ... is out on the streets, they're clearing streets, they're bringing law and order," Clinton said.
NBC News and The Associated Press contributed to this report.