A “much loved” school therapy dog died after being left in a hot car for six hours because of a staff mix-up.
Labrador Ruby had been helping lower-ability pupils at Sittingbourne Community College in Kent three times a week since 2010.
Owner Dave Carden, 53, a PE teacher, routinely took her in each day and left her in his car for another teacher to collect and take into class.
But on Tuesday - one of the hottest days of the year so far - she was not collected and remained in the car from 8am to 2.35pm.
Outside temperatures rose to the 20C mark and by the time Carden returned to his car, five year-old Ruby was dead.
He rushed her to the vets but there was nothing they could do to save her.
Jon Whitcombe, principal of Swale Academy Trust which runs the college, said many pupils had been devastated by the "tragic accident".
He said: "Ruby was a much-loved member of the school community and died in what can only be described as a tragic accident.
"We've got a number of very upset pupils and staff and we're trying our best to provide the necessary support to those concerned."
The RSPCA has launched an investigation and a spokeswoman said: "We received calls about this incident - from members of the public rather than the police.
"We are currently looking into the matter, so cannot say more about the specific incident at present."
Ruby was presented with a young carers' community award in 2011.