Irish aid worker Dominic McSorley says Haiti is like a war zone.
McSorley - who is heading up efforts by Irish American aid agency Concern Worldwide - says the smell of death is overwhelming.
"When you're driving past and seeing bodies on the road and people crying, it's like a war zone," he told the BBC.
"The impact that this is having on this small country - nine million people and a third of the population affected - this is the biggest disaster in this nation's history.
"It is very confusing and people are still dazed. I do think we are going to start seeing a big difference in the next couple of days, in fact I know we are."
Concern maintains supplies in Haiti and is working on getting aid out to the right people.
"Sixty thousand people got food yesterday," he said. "If we can get the aid out, the situation will calm down."
Many have lost their families and many have lost their homes. They are sleeping out in the rough," he said.
"There are a lot of mixed emotions, but you don't have much time to think about it and perhaps that is the best thing."
MsSorley is also tweeting from Haiti at www.twitter.com/aidwkr and today he reported that thousands of people have jammed the airports in their efforts to get out of the quake-hit country.