Hurricane Katrina, one of the largest and strongest storms on record, roared onto shore this week, causing massive devastation in Louisiana, Alabama, Mississippi and other states. But another danger to the region is still brewing. With storm surges of up to 20 feet in some areas, huge petro-chemical plants, gas stations and waste pits have unleashed a toxic cocktail of chemicals ranging from vinyl chloride to gasoline.

Take Action! Natural disaster or terrorist attack - Tell Congress to act NOW to prevent more tragedy.

Already nicknamed "Cancer Alley," the polluted area now suffers from contaminated flood waters of up to 20 feet - which can affect homes, drinking water and surrounding waterways. In New Orleans, the city's levee system is now serving only to hold water in the city, creating a temporary lake of toxic chemicals, gas, oil and storm debris.

Deputy director of the Louisiana State University's Hurricane Center, Ivor van Heerden, warns, "We're talking about an incredible environmental disaster… a bowl full of highly contaminated water with contaminated air flowing around and, literally, very few places for anybody to go where they'll be safe."

I've been working for Greenpeace for more than 14 years to prevent just this sort of tragedy. No one could stop Katrina, but chemical plants like those found in Cancer Alley and around the nation can be converted to safer technologies. Natural disasters, chemical spills during transport and the threat of chemical terrorist attacks are reason enough. The good news is that toxic chemicals such as chlorine, which are used to make these pollutants, have many safer alternatives - it's time to make the switch.