The U.S. military has sent 19 helicopters to the hard-hit northwest to help distribute aid supplies, but the monsoon rains have kept them grounded. The helicopters have only been able to fly relief missions three days out of the last nine. There are more than 400 tons of flour, rice and baby formula waiting to get to the affected areas, but as long as the helicopters are not flying, the aid is not getting to those who need it.
Army pilot Maj. Dan Rice was rushed to Pakistan from Afghanistan to help. His squadron, loaded with supplies, is going nowhere.
"It's extremely frustrating." he told ABC News. "We know there's people up there who need to get to safety."
All Maj. Rice can do now is wait for the rain to relent.
"Each of the helicopters is already loaded and ready to go. So the moment we have a chance to go, we are prepared, we're briefed and we'll be in the helicopters moving," he said.
The scope of the devastation is staggering. Six million people survived the floods, but now are in dire need of aid. Two million people are homeless and a fifth of the country remains underwater. Infrastructure has been wiped out, two years of crops washed away. The river Indus, in the south of the country, has swelled to 25 times its normal width for this time of year.
The United Nations says that the number of people affected makes this disaster worse than the 2004 Indian Ocean tsunami, the 2005 Kashmir earthquake and the Haiti earthquake combined.
At least 1,500 people have died and tonight the U.N. is warning of a second wave of deaths from water-borne diseases like acute diarrhea, cholera and polio. The children's hospital in Multan has already seen a thousand cases.
"Before the floodwater normally we checked only 40 children a day," said Dr. Mukhtar Hussein. "Now the number has doubled."
"Children are dying now as we speak because of lack of access to clean drinking water," said Pascal Cuttat of the International Committee of the Red Cross.
Pakistan's Floods: A Fifth of the Nation Underwater
Anger is being directed at government leaders, mainly President Asif Ali Zardari. Last week he visited Europe, even stopping at a family-owned chateau in France, while the flood waters rose back at home. The Pakistani president made his first visit to the affected areas yesterday.
President Zardari will likely be under fire again: it was announced today that the he will be shortening an upcoming trip to Russia -- not canceling it. The president will, however, cancel Pakistani Independence Day celebrations scheduled for tomorrow in order to spend the day with flood victims.
Today, local television reported warnings for villages along rivers in Sindh and Punjab provinces and there is still the threat of more dam breaks. The evacuations are well underway.
"Out of a population of 300,000, about 225,000 people have left to nearby cities and towns in the past few days," said Sindh city administrator Kazim Jatoi.
More floods bringing more danger, and more urgency for those relief missions to fly.
The Associated Press contributed to this report.