The flooding caused by unprecedented rainfall in South Carolina has killed 11 people. More than two feet (60cm) of rain have fallen in the past three days in parts of the state.

South Carolina floods
A church is engulfed by floodwaters in Columbia, South Carolina Sean Rayford/Getty Images

"This is a Hugo-level event," said Major Gen. Robert Livingston, head of the South Carolina National Guard, referring to the September 1989 hurricane that devastated Charleston. "This water doesn't fool around."

Hurricane Joaquin missed the East Coast, but fuelled what experts at the National Oceanic and Atmospheric Administration called a "fire hose" of tropical moisture aimed directly at the state.

Of the 11 people known to have been killed, seven drowned, the South Carolina Department of Public Safety said. Four others died in weather-related car crashes, the agency said. A state transportation department employee was killed after his work truck was overturned and swept away by rushing waters.

The flooding closed schools and government offices, stranded motorists and led to dramatic rescues, including that of a mother and her 15-month-old baby who were plucked by a US Coast Guard helicopter from their flooded home in Huger, South Carolina.

Some towns have been entirely cut off. All four roads leading into the county seat of Manning are closed, isolating 4,000 people.

Officials in Columbia ordered areas south of a breached dam to evacuate. Richland County Sheriff Leon Lott said workers are going door-to-door in some areas, ordering people to leave their homes. He said the high water and swollen rivers are breaching dams so quickly that workers are having difficulty keeping up.