Michael Barratt, executive principal of The Priory School in Shrewsbury, said he felt deeply for the youngsters who now faced a time of uncertainty as the Government worked out a system of awarding qualifications.
Prime Minister Boris Johnson announced on Wednesday that all schools would shut from the end of today, with provisions for vulnerable pupils and the children of key workers, and that there would be no exams – including GCSEs and A-levels – taking place during the summer.
He said the Government would devise a way of ensuring that pupils will get the correct qualifications, but the full details have yet to be revealed.
Mr Barratt said it was right to close schools if it was necessary for public safety, but he felt for those in their final year who would not be sitting their exams now.
"It is the right thing to do, in that we trust the scientists and we trust the Government to make the right decision for the nation," he said.
"But I really feel for so many students who have worked extremely hard over a long period of time not to have the opportunity to perform in exams.
"They will now experience a period of uncertainty while they come up with a way of deciding what qualifications they get."
Mr Barratt added that his final-year pupils had shown a great deal of dignity and maturity in the way they had handled the difficult situation.
He said he did know how the Government would work out how the qualifications were awarded, but he said the over-riding aim had to be to ensure fairness.
"There are different ways of working out what qualification you get," he said. "The main thing is that it has to be fair."
Mr Barratt said the school would fully support its pupils during the closure programme.
"We have also set up, through our software, user-friendly access to resources and work that will be set and assessed by teachers during that period of time," he said.
Under the closure plan, schools will be shut to most pupils from the end of today, although an exception will be made for the children of 'key workers'.
Reuben Thorley, headteacher of The Community College, Bishop's Castle, said the decision was probably necessary, although he would have liked more clarity the scheme for children of 'key workers'.
"If we knew which parents and which children we would be working with, we would have more idea of the numbers, and we would have been able to plan for staff numbers," he added.
Mr Thorley said he hoped that any ways of calculating pupil's exam grades would make use of teachers' own assessment data, and then adjusting it to match school performance.
He added that a programme of work had been lined up for pupils during the closure period in line with the normal curriculum.
"We suspected this was going to happen, so we began prepping the students last week," he said.
Rachel Cook, headteacher of Newdale Primary School in Telford, said the school would continue to support its patients throughout the closure period.
Miss Cook said her teachers had produced a work programme that pupils could carry out over the closure programme. This would mostly be online, but alternatives would be provided where necessary.
Meanwhile, a Shropshire MP asked the Government to look at whether it could do more to support local government in supplying children who were entitled to free school meals.
Mark Pritchard, MP for The Wrekin, said Telford & Wrekin Council was responsible for providing 5,300 free school meals every day, but now without access to the school canteens.
"I just wonder what more the Government can do, given that many volunteers, and many working in charities that might be offering to backfill those places where they might need support, might be self-isolating," he told Environment Secretary George Eustice in the Commons yesterday.
Mr Eustice said the Government was setting up a national body to co-ordinate the many offers of volunteer-help that had been received. He said it was also working with the supermarkets to expend their home delivery and click-and-collect services.