Something has gone "seriously wrong", a council chief admitted after an elderly woman suffering from Alzheimer's was left locked in a minibus overnight.
The woman, who is in her 80s, was picked up from the Hockwell Ring Day Centre in Luton on Monday afternoon and should have been taken home to her flat at Jill Jenkins Court, a home for the elderly that offers 'extra care'.
Instead, she was found by a driver at 7am on Tuesday morning locked inside the Luton Borough Council minibus in the city's Kingsway depot.
She was returned home shortly after being found and is not thought to have been injured.
The council has launched an internal investigation into the incident and the driver of the minibus has been "suspended without prejudice", a council statement said.
Trevor Holden, the council's chief executive, said: "Senior officers from the council met with our client's family as soon as possible on Tuesday to make sure everything is being done for her continued welfare and to express how very, very sorry we are that this appalling incident took place.
"We are deeply shocked that something has gone so seriously wrong and we will do everything we can to find out exactly what took place and ensure it cannot happen again."
A multi-agency adult safeguarding meeting organised by the council took place on Wednesday to investigate how the woman was left on the minibus, why an alarm was not raised earlier and to ensure immediate action had been taken to safeguard all users of the service, the council said.
In accordance with adult safeguarding policy, Bedfordshire Police will complete its initial investigation and then each organisation will proceed further with its own internal investigations relating to the woman's care.
Mr Holden added: "We deeply regret the distress caused to everyone affected. Action will be taken.
"The family members are understandably distressed and we are providing ongoing round-the-clock support for them.
"We are also taking extremely seriously our duty of care towards our member of staff."
The council has immediately put a temporary procedure in place to ensure every passenger transport vehicle is checked before the end of each day, and this will remain in force until further notice.