Rescue teams and emergency supplies are headed to Haiti by air and sea today in a global response to the catastrophic earthquake feared to have killed more than 100,000 people. But it is diifficult to really know just how many people have died and how many are trapped beneath the rubble. The Red Cross estimates three million Haitians need immediate relief - with food and clean water supplies running out quickly. The next few hours are crucial to get help onto the streets of the capital Port au Prince and elsewhere.