"Because I have been busy writing two catalogues, I haven't been able to follow the news on what exactly happened but I know the Basilica well. If the work you describe has been damaged then it is a great mutilation to the international artistic heritage. This period of work at the end of the 13th and the beginning of the 14th centuries represents the beginning of European painting. It is when modern art - in the sense of modern, not contemporary - starts. Fortunately, in the Basilica, the frescoes along the walls seem to have been saved. But, it is like when a human body loses an arm.

I have full confidence in the restoration system in Italy but you have to refer to what is left. The frescoes would have collapsed from a height of 20 metres which would mean the fragile material would be almost in crumbles of soil. Some large pieces may be recovered but you can't reconstruct what is lost. For example, there is a restored Crucifix by Cimabue in St Croce church in Florence which was destroyed during floods in the 1960s and 30 to 40 per cent of it remains missing.

Fortunately, the Basilica is full of frescoes by all the major artists of that time from Italy and Europe so for the non-expert visitor it is not an enormous loss but for the professional like me, it is a catastrophic loss."

Patrick Pye, painter and stained glass artist:

"It's very shocking what happened. If (as you say) there have been only two Giotto frescoes in the vault above the altar damaged, that's very fortunate because his main work in the Basilica is the cycle of frescoes on the life of St Francis in the nave. This is very beautiful, very lyrical and it is comparatively early work of Giotto's. If that has escaped, it's wonderful. Although I doubt if some of it hasn't been damaged. I read a description of the earthquake which said that it was as if the church was lifted up and bashed down again.

Giotto was the central figure for Western civilisation. He made his art from the vision of St Francis. He was responsible for a theological about-turn from the medieval period. Giotto was said to be the father of modern art even though a lot of people don't know his paintings, he has had an incomparable influence on painting. Cimabue (whose fresco is also believed to be seriously damaged) was also a wonderful painter.

It's amazing what restorers can do now. Their work is very technically sophisticated. It would be tragic if these frescoes are lost. If European money can be found to restore them, it should be found."

Vera Ryan, lecturer in art history, Crawford College of Art and Design, Cork:

"Apart from the human tragedy of four people - two monks and two restorers - who were killed there, I feel the artistic loss is mind-boggling. It seems that the restoration of these fabulous frescoes may not be possible, the damage is so extensive. Assisi is such a hugely significant art site and these works so particularly beautiful, it is a loss that I can't quite believe has happened in my lifetime. I was looking at them in July and I can't believe that when I get back there next July, they won't be there as they have been for the last 600 years."

In conversation with Sylvia Thompson