There had been 19 outbreaks since 1995.
The letter did not indicate plans to step up inspections. Instead, it called on the industry to take "the appropriate measures to provide a safe product."
One year later, outbreak No. 20 — the spinach — killed three and sickened more than 200.
A former FDA deputy commissioner says the agency is so understaffed it has little capacity to prevent outbreaks, even predictable ones.
"I think basically FDA right now is really not able to protect the safety of the food supply the way people expect," Michael Taylor, the former FDA deputy commissioner for policy, told CBS News.
An anonymous tip alerted the FDA to salmonella in a ConAgra factory more than a year before the peanut butter made there sickened 400 people.
Investigators visited the plant but didn't press ConAgra to explain why it had recently destroyed a batch of peanut butter.
Part of the problem, critics say, is that in recent years food has take a back seat to drugs at the agency charged with regulating both.
"Sadly, today this great Food and Drug Administration, when it comes to food safety, has become the weakest link," said Sen. Richard Durban, D-Ill.
Just compare the FDA to its sister agency, the U.S. Department of Agriculture. The FDA is responsible for 80 percent of the nation's ever-growing food supply; the USDA for the other 20 percent. And yet the USDA has five times the number of inspectors.
"If products are regulated by FDA, like seafood and produce and grains, they might only see an inspector once every five or 10 years," said Caroline Smith DeWaal of the Center for Science in the Public Interest.
That's why this month, in the wake of the E. coli outbreak, the California produce industry imposed standards on itself — far more strict than the FDA's rules.
"We didn't wait for regulation or legislation. That can take a lot of time to do," says Joe Pezini of Ocean Mist Farms. "Even the government has said this is the fastest way to enact change."
The Bush administration's budget calls for an additional $11 million for FDA food safety efforts next year. Former FDA officials say the agency needs 10 times that.
Meanwhile, CBS News correspondent Wyatt Andrews reports that the FDA isn't just under fire for how it handles food – the drug part of its safety mission is also under attack in Washington – and for the same reason: The agency doesn't take action until after someone gets sick or dies.
"There is a saying: 'The history of the FDA is written in tombstones,'" says Bill Vaughan of Consumers Union.
For example, researchers connected Vioxx to up to 140,000 heart attacks before the FDA pulled it from the market. With Baycol, the death count was 31. The drug Rezulin caused 28 deaths before it was recalled.
One reason is the FDA is not allowed by law to require a drug safety study after a drug is released to patients market. And even after the FDA learns of problems, it has to ask the drug manufacturer for a changes on the label.