The Haitian prime minister said Wednesday several hundred thousand people may have died in Haiti's powerful earthquake, CNN reported.
"I hope that is not true, because I hope the people had the time to get out," Jean-Max Bellerive told CNN.
"Because we have so much people on the streets right now, we don't know exactly where they were living. But so many, so many buildings, so many neighborhoods totally destroyed, and some neighborhoods we don't even see people."
He said the population is calm as authorities try to adjust to the scope of the destruction and reach a better conclusion on how many people were killed or injured.
"With maturity, people are trying to take care of themselves in some quiet places. People are trying to help each other on the streets," he said.
Earlier, Haiti's first lady, Elisabeth Debrosse Delatour, reported that "most of Port-au-Prince is destroyed," the Haitian ambassador to the United States, Raymond Joseph said. He called the quake a "major catastrophe."
U.N. Secretary-General Ban Ki-moon spoke of the collapse of "basic services such as water and electricity."
Authorities braced for civil disturbances.
Edmond Mulet, the U.N. assistant secretary-general for peacekeeping operations, told CNN that the National Penitentiary collapsed and the inmates escaped, prompting worries about looting by escapees.
About 3 million people -- one-third of Haiti's population -- were affected by the quake, the Red Cross estimated. About 10 million people felt shaking from the earthquake, including 2 million who felt severe trembling, the U.S. Geological Survey estimated.
President Obama pledged Wednesday that the U.S. government would lead "a swift, coordinated and aggressive effort to save lives" in Haiti after the earthquake.
"For a country and a people who are no strangers to hardship and suffering, this tragedy seems especially cruel and incomprehensible," he said.
The president noted that "military overflights have assessed the damage" from the earthquake and that civilian disaster assistance team were beginning to arrive in Haiti.
Obama said U.S. relief efforts are currently focused on a quick accounting of U.S. Embassy personnel and their families in Port-au-Prince, as well as other American citizens living and working in Haiti. He urged Americans trying to locate family members in Haiti to telephone the State Department at 888-407-4747.