Vehicles were trapped in hail drifts
East Devon and parts of Cornwall have been hit by serious flooding after a night of storms, including severe rain and heavy hail.
Devon and Somerset fire service described the situation in the Ottery St Mary area as "absolute chaos".
Police said that a pregnant woman, who had gone into labour, had to be rescued from a car and about 25 people have been rescued from their homes.
An evacuation centre has been set up at the hospital in Ottery St Mary.
A police spokesman said: "There have been a series of weather-related road collisions.
"This included a road accident near Honiton with a female giving birth who had to be transported by ambulance to the Royal Devon and Exeter Hospital."
He said "many" vehicles, including a 38ft-long (11.6m) lorry, had been trapped in flood water.
Devon and Somerset Fire and Rescue Service said 25 people had been rescued from flooded homes in Ottery St Mary and Feniton.
Susanne Reed, from the fire control centre, said it was the worst flooding she had seen in 25 years.
"It has been absolute chaos, it started just after midnight when we were out rescuing people stuck in their cars in flood water.
"It got worse and worse and one crew got stuck in a 6ft (1.8m) [hail] drift," she said.
She added that crews had been rescuing people "constantly" and she could not begin to say how many had been helped to safety.
A spokeswoman for Portland Coastguard said coastguard volunteers had rescued a family of three who were trapped in a bungalow, using their four-wheel drive vehicles.
She said they also rescued several elderly people from a housing estate.
They have been taken to the hospital in Ottery St Mary.
One resident who spoke to BBC News from her home just outside Ottery St Mary said: "There is 2ft 6ins [0.75m] of water on the road. I can't get out of the house."
John and Joan Burrows, who farm nearby, have lost about 30 sheep. Joan said: "Others are sheltering on the old railway line and we're hoping they don't try and jump in the water."
Tony Fabry, who runs the town's post office, said: "At one point I was watching beer barrels, sandwich boards and even a children's slide floating down the road.
"It was absolutely horrendous."
The town had been preparing for its bonfire night celebrations
The town had been preparing for a carnival this weekend, ahead of its annual Tar Barrel Rolling festival on 5 November.
Devon and Cornwall police warned motorists that roads in the area were "treacherous" and a number of routes had been closed because of flooding or ice.
In Boscastle in Cornwall six premises were flooded overnight because of a blocked storm drain.
Heavy rainfall has also led to problems with surface water on Cornwall's roads.
The Environment Agency has flood warnings in place on the Rivers Otter, Axe, Clyst, Coly, Culm, Isle and Yarty in Devon.