Federal health officials say California reported the death, but they did not provide other details.
The government now has reports of 121 people who got sick in 25 states. At least 52 people have been hospitalized, including 14 with kidney failure, which is an unusually high number of hospitalizations.
READ MORE: Throw away romaine lettuce if you don't know where it came from, CDC urges amid E. coli outbreak
The Centers for Disease Control and Prevention updated the numbers Wednesday.
Kentucky, Massachusetts and Utah were added to the states with reported cases.
Health officials have tied the E. coli outbreak to romaine lettuce grown in Yuma, Arizona, which provides most of the romaine sold in the U.S. during the winter.