Relief has begun trickling into quake ravaged Haiti but impassable roads and a heavily damaged airport have left eager aid workers largely unable to get food, water and rescue workers into Port-au-Prince.
President Obama spoke directly to Haitians today and tried to give them hope, saying he could understand why they would "look up and ask have we somehow been forsaken."
"You have not been forsaken. You have not been forgotten," the president said. "Today you must know help is arriving."
Obama said the U.S. is launching "one of the largest relief efforts in our recent history," but he acknowledged it may be an excruciating few days before it can arrive where it's needed because "roads are impassable, the main port is badly damaged and communication is just coming on line."
Desperate and exhausted Haitians have taken it upon themselves to help each other with whatever they could find until skilled workers reach them.
In a particularly hard-hit section of Port-au-Prince late Wednesday, a group of men worked into the night with only a crowbar and the light of a video camera to free a woman who was buried in the rubble of her office building. She repeatedly called out to them, directing them as to where exactly she was in the mountain of concrete and debris.
Once open spaces in Port-au-Prince are now crammed with victims. Many have no homes to go back to and those who do are terrified to go inside for fear that aftershocks will collapse the walls and entomb them.
Ricardo Dervil, 29, said he joined the crowds simply roaming the wrecked city.
"I was listening to the radio and they were saying to stay away from buildings," he said. "All I was doing was walking the street and seeing dead people."
Staff from damaged hospitals are treating the injured in tents and parking lots as streams of new patients are brought in in trucks or carried on doors turned into stretchers.
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"This is much worse than a hurricane," said Jimitre Coquillon, a doctor's assistant working at a makeshift triage center set up in a hotel parking lot. "There's no water. There's nothing. Thirsty people are going to die."
Reports on Twitter gave poignant details of the devastation.
"The hospital across the street is putting bodies out on the street. decomposition. we need portable morgues. generators. food. help. Evacuation," tweeted Richard Morse.
At dawn today, Morse added, "the singing and praying has begun. we won't begin to understand all that is going on around us for some time to come."
Morse also said he had received reports from the town of Jacmel that "a school collapsed w/children inside."
Pooja Bhatia tweeted from Port-au-Prince's Plaza Canape Vert. "refugee camp. smells like human waste, creeping smell of death," she wrote.
She later added, "every aftershock in teh canape vert plaza makes people cry and pray no one can sleep."
The quake struck late Tuesday afternoon, its epicenter just 10 miles from the densely-populated capital. It had a magnitude of 7.0, making it the worst earthquake to hit Haiti in 240 years.
Death toll estimates have fluctuated wildly, with Haitian officials throwing out numbers from 30,000 to as many as 500,000 people. There are an estimated 45,000 Americans living in Haiti. The State Department has so far confirmed three American deaths from the earthquake.
"Our hearts and our prayers go out to them," she told "Good Morning America" today. "The U.S. is going to be there, not just for today, but for the weeks and months and years ahead."
Clinton declined to estimate how many people died in the earthquake, but said it is estimated the disaster affected 3 million people.
World Vision spokeswoman Maggie Boyer said the city is overwhelmed by the number of people who don't know what to do next.
"I think the city is beginning to show signs of real displaced people who are just roaming and roving throughout the streets unsure of where to go," she said.
President Obama has promised a full military and civilian response to Haiti.
The U.S. Navy aircraft carrier Carl Vinson and the destroyer USS Higgins are expected to reach Haitian waters today, along with members of the 82nd Airborne Division. Up to 1,000 U.S. soldiers will arrive in Haiti over the next 24 hours and 2,200 will be deployed by Sunday. Several other ships, including a large hospital ship have been prepped for possible deployment.
Among the first of the oustide relief to reach Haiti was an Air China plane that was able to land at the Port-au-Prince airport. More than 50 members of a search and rescue crew along with trained dogs quickly got to work. China said the plane also carried medics, seismological experts and 10 tons of food, medicine and other supplies. Many of the Chinese sent to Haiti were experienced in dealing with such a disaster, having worked on China's 2008 quake that killed nearly 90,000 people.
They joined rescue units from France and Spain as well as Fairfax, Va., which had arrived on Wednesday.
Clinton called the earthquake particularly devastating because it came at a time when Haiti was just starting to rebuild it's infrastructure and economy for a series of devastating hurricanes in 2008.
New buildings had been going up and businesses were returning to Haiti, Clinton said, all part of a plan Haitian President Rene Preval had brought to the United States and the United Nations.
"We have seen this cycle of hope and despair so many times," Clinton said. ""Perhaps with this increased attention, we really can help Haiti rebuild."
"Thankfully the people of Haiti are a resilient people," she said.
Tuesday's earthquake was the ninth major natural disaster to slam Haiti in nine years.
So far there have been no reports of widespread looting or violence, but those on the ground worry that if aid doesn't start to reach the people soon, the fear and desperation may cause a wave of unrest.
Boyer said the sense of calm and order among even the most hard hit victims has been a very encouraging sign.
"We are just really trusting that that situation will remain the same," she said.
Raymond Joseph, the U.S. ambassador to Haiti, told "Good Morning America" today that as of now the U.S. military has not been asked to help provide security around Port-au-Prince, but rather to focus on helping its distraught, injured and hungry residents.
"[We] will probably be able to clear the debris from the roads," he said. "Once that is done we'll see more coordination on the ground."
The airport, he said, is also expected to be fully functional later today.
American missionaries have begun reaching the Port-au-Prince airport hoping to get on a plane leaving Haiti. Most don't have a plan, but are just hoping an opportunity will come.
"There's just no commercial flights," one American missionary out of Miami told ABC News. "We're hoping maybe a military plane will get us home. Go to the Dominican Republic and hope for a plane out of there."
The Associated Press and ABC News' Lee Ferran, Kate McCarthy, Monica Nista, Luis Martinez and Sarah Netter contributed to this report