UNITED NATIONS - The UN secretary-general joined the world's leaders Wednesday in expressing shock over the sheer scale of the earthquake in Haiti that has toppled hundreds of buildings, killing an unknown number of people and leaving an already impoverished nation of 9 million people in chaos.
"Medical facilities have been inundated with injured. There is no doubt that we are facing a major humanitarian emergency and that a major relief effort will be required."
Ban called for an immediate international response, releasing $10 million from the Central Emergency Response Fund.
He said UN agencies have been working since the quake struck Tuesday, although the UN mission in Haiti has suffered casualties.
The UN's special representative in Haiti, Hédi Annabi, and his deputy, Luiz Carlos da Costa, are still missing.
The UN has about 9,000 troops on the ground as part of its United Nations Stabilization Mission in Haiti.
Those relief efforts have been hampered by an already poor infrastructure now further damaged by the quake.
Ban said electricity and water supplies have broken down almost entirely.
The UN headquarters at the Hotel Christopher in the capital, Port-au-Prince, collapsed.
"I am grateful to those countries that are sending emergency relief," Ban said. "I urge all members of the international community to come to Haiti's aid in this hour of need."
Andrew Morton, a UN staffer working on reforestation, freshwater and other ecosystems for the United Nations Environment Program based in Haiti, said in a statement: "The quake was a direct hit on the city. Destroyed buildings are everywhere, walls collapsed, roads blocked et cetera. Casualties will be in the many thousands."
Humanitarian nongovernmental organizations and private charities are rushing into the fray, too.
"I know the country and I know Haiti is bad in good times," said Pastor Donald Havrilla of Southampton Full Gospel Church in Southampton, which has operated Mission Reach Out Haiti for nearly 40 years.
"This human suffering has been going on for years."
Havrilla has not been able to reach any of his staff members since the quake struck, but he said he hopes to contact elected officials to help him get to his mission, which is east of Port-au-Prince in Leogan.
"We're very concerned," he said, adding the mission employs about 100 people and serves more than 1,400 children.
"I know some of these people since they are 6 years old and now they're 35."
Louis Belanger, a spokesman for the international relief agency Oxfam, said in Manhattan that military flights are the only aircraft allowed into Haiti right now because the airport is not functioning.
Oxfam has about 100 people in Port-au-Prince and one staff member is missing, Belanger said as he prepared to leave to help with the humanitarian effort.