Hurricane Katrina savaged southern Louisiana 18 months ago, but only recently has regular residential trash pickup resumed at Sandy Rosenthal's home in central New Orleans.

Located on high ground near the Mississippi River, the former North Attleboro resident's home escaped the catastrophic floods that destroyed thousands of homes, took hundreds of lives and wrought billions of dollars in damage in August 2005.

But like most others in New Orleans, Rosenthal continues to be haunted by the extent of destruction in her adopted city - and a persistent shade of opinion that lays much of the blame for the disaster on local officials and New Orleans residents themselves.

Rosenthal, 49, is mad as hell and isn't taking it any more.

As an activist and founder of www.levees.org, she has held community meetings, conducted rallies and posted links to reams of documents and news stories on the Web supporting what many in the devastated city fervently believe: that the destruction was a man-made disaster wrought by flimsy flood control levees built by the federal government and neglect by both Congress and the Army Corps of Engineers. "America doesn't understand," Rosenthal said in a telephone interview from her New Orleans home. "Katrina missed us."

The killer storm, billed as the worst to ever threaten southern Louisiana and Mississippi, actually came no closer than 30 miles. Although the winds were strong, Rosenthal said the gusts were insufficient to strip papaya fruit from a tree in her yard.

Nevertheless, catastrophic breaches in the levees sent water cascading into neighborhoods and dealing unprecedented death and destruction, especially in Lakeview and New Orlean's Lower Ninth Ward.

Much of the city remains devastated, both by mountains of rubble and memories of residents lost in the flood.

"Everybody here knows someone who drowned, or knows someone who knew someone," Rosenthal said.

She and many others believe it needn't have happened.

Over the past several decades levees and other flood control projects designed to keep water from the Mississippi River, Lake Pontchartrain and a system of canals out of low-lying New Orleans have been built and maintained by the Corps of Engineers with funding from Congress.

In the months since the storm, Corps officials have contended that Katrina overpowered a system that was not designed to protect the city from anything greater than a Category 3 hurricane. The Corps placed much of the blame on failures near Pontchartrain caused by overpowering flood surges that it says overtopped the floodwalls.

But since the storm, a growing parade of engineers, universities and other critics have come forth with evidence of what they call faulty construction and have begun to question whether the primary cause of the New Orleans disaster was weather or error.

A review panel convened by the American Society of Civil Engineers rejected the Corps' claim that Katrina had unleashed unforeseen forces that weakened floodwalls, and cited previous studies by the Corps, itself, predicting the very causes resulting in the breach of the city's 17th Street Canal floodwall. Investigators from Louisiana State University concluded that floodwalls near Lake Pontchartrain were not overtopped by flood surges as claimed by the Corps, raising the possibility that the failures that led to the most damaging flooding stemmed from poor design.

Other critics have questioned the sturdiness of so-called I wall construction common in levees in New Orleans, instead of stronger and more expensive T-wall construction. Similar construction is also used in other levees around the country.

The Corps' public affairs office in Washington, D.C., did not return a call seeking comment.

Like thousands of others in New Orleans, southern Louisiana and Mississippi, the storm sent Rosenthal, her husband and their 15-year-old son scurrying to get out of the way.

Rosenthal, who moved to New Orleans after college 26 years ago, heard the storm warnings and bundled into the car along with her family and two elderly neighbors and headed for Jackson, Miss. The Rosenthals later moved on to Lafayette, where they remained until December.

Rosenthal returned more committed than ever to her adopted city.

"People are so friendly here in the way they treat everyone," she said. "There's the beauty, the culture, the climate. I feel like I fit here."

Galvanized by negative publicity and what she refers to as "blame the victim" psychology, Rosenthal launched www.levees.org in December 2005 with her son, Stanford, as webmaster.

She also organized town hall-style meetings, news conferences and rallies in an attempt to set the record straight and hold Corps officials and Congress to account.

She hopes to build support for an investigation not unlike the 911 commission to determine what went wrong and to encourage a greater response in the form of federal dollars to help rebuild.

So far, www.levees.org has attracted more than 10,000 members who support better flood control protection in the form of secure levees. And Rosenthal says New Orleans residents aren't the only ones with a stake in determining whether the Corps' flood control projects contain serious flaws.

According to a recent USA Today article, the Corps controls a total of 146 levees in all 50 states - including several in Massachusetts - that could pose unacceptable failure risks in a major storm.

"We want to create a national awareness so that other cities don't meet the same fate as New Orleans," Rosenthal said.