Record-breaking rains and flash floods in Louisiana have killed five people, washed away sections of highway, collapsed a bridge and forced thousands to flee their homes. The torrential rains are expected to continue for at least two more days.

Great swathes of the low-lying southern section of the state along waterways are inundated with flood water and Bossier City is almost completely submerged.

Officials have ordered 3,500 homes be evacuated but hundreds of residents have no safe way to leave. Some are drifting down waterways on top of anything that floats — while large fish can be seen swimming over spots that used to be dry pavements.

Emergency workers are trying to get to stranded residents by boat.

Over 20 inches (50cm) of rain have drenched the Red River area around Shreveport, triggering the mobilization of the National Guard. Governor John Bel Edwards declared a state of emergency for several parishes

"Thirty years I've been here, it is probably epic, probably the worst," Captain Mike Carman told CBS News. "And with what we have coming in it is probably going to be more."

Two men drowned when the cars they were driving were suddenly swept away by flood waters. A six-year-old girl died when her mother lost control of her car in raging waters.