An elderly woman has died after the car she was in slid into the water at the King Harry Ferry crossing and couldn't be retrieved for two hours.
The driver of the vehicle managed to escape. It is thought he left the car on the slip leading to the ferry in order to take a photograph, when his car slipped forward into the causeway.
The Carrick Roads, as the channel is called, stretches from Falmouth to Truro and is famous for its size and depth.
It has the third largest natural harbour in the world at its mouth, and in parts depths reach up to 34 meters.
The King Harry Ferry website has released the following statement: "Our thoughts are with everyone involved after a car came off the Roseland slipway side of the King Harry Ferry."
The ferry connects St Mawes and the Roseland Peninsula with Feock, Truro and Falmouth by avoiding the alternative 27 mile route through Truro and Tresillian.
A diver is understood to be currently carrying out an underwater search.
The King Harry Ferry Company issued the following statement:
"We can confirm that at 16.00 on Wednesday, March 20, a
car on the Roseland side on the river Fal entered the water from the slipway.
"The King Harry Ferry was at the Feock side of the
river at the time.
"The service has been temporarily suspended and emergency
services are in attendance."
Reports from the scene suggest that one person was in the car when it went into the river.
The car is thought to have been completely submerged for approximately 30 minutes.
Emergency services are rushing to the scene after a car went into a deep flowing river in Cornwall.
The car went into the Carrick Roads at the site of the King Harry Ferry.
The car is understood to have gone straight into the river from the road on the Roseland side.
Ambulance personnel, fire crews, the coastguard and the police are all understood to be at the scene.