The window was closing as search teams tried to rescue the dying victims of Haiti's earthquake before they become the dead, and governments around the world were rushing to get in aid supplies.
Several people, one of them a months-old baby who will be brought to the United States, were pulled alive today from the rubble.
But looting and violence were increasing, too, possibly jeopardizing rescue and aid distribution efforts.
The Haitian government said 20,000 bodies have been collected already, and officials expect the final number of victims from Tuesday's earthquake could reach 100,000, at a minimum.
At least 15 Americans were known to be dead, and late today the United Nations confirmed that its mission chief in Haiti, Hedi Annabi, died in the earthquake.
Haitian authorities estimated this morning that as many as one million people were homeless and 250,000 were wounded.
Amid the growing despair and desperation, President Obama enlisted his two presidential predecessors -- presidents George W. Bush and Bill Clinton -- to lead an American fundraising effort for Haiti.
"The country is in total chaos. The government is totally inexistent," Max Beauvoir, Haiti's high priest of Voodoo, wrote to ABC News' Jake Tapper in an e-mail. "Law and order no longer exist. ... How can the suffering ones expect to receive directly some humanitarian help?"
ABC News witnessed a violent street fight and spent time on a food line where tempers flared.
Seismic aftershocks continued to jolt Haiti, including a 4.5-magnitude event that shook Port-au-Prince and briefly halted rescue efforts this morning.
Some Haitians complained that foreign victims were being saved first -- particularly in light of multiple rescues from the rubble of the upscale Hotel Montana.
In many areas, families desperately searched for loved ones with only hand tools or whatever they had available.
One sign on a collapsed building said, "Welcome U.S. Marines. We Need Help. Dead Bodies."
Still, there was reason for hope, even four days after the main earthquake.
There were 26 international search and rescue teams on the ground in Haiti, U.S. officials said this morning. Four of them were American, and they had rescued at least 15 people as of the morning.
In addition, American rescue workers pulled Saint-Helene Jean-Louis, 29, from the rubble of the Port-au-Prince university later in the day.
And rescuers pulled another woman from her destroyed home this afternoon, though her eight children died.
"Search effort continues in full force," said Tim Callaghan, senior regional adviser for Latin America and the Caribbean at the Office of Foreign Disaster Assistance, who was spearheading U.S. operations on the ground.
"U.S. teams along with other international teams are continuing rescue efforts today and that will certainly continue [Sunday]," Callaghan added.
Late today, ABC News climbed through the remains of an apartment building where people said the voices of the survivors still could be heard.
From the rubble of an office building, a woman named Christine was signaling she was alive by clicking the remote control on her key chain and texting her friends.