ASSISI, Italy (Reuter) - The shocked Italian town of Assisi on Sunday mourned two surveyors killed in the Basilica of St Francis when a devastating earthquake rocked the region. The two men, Bruno Brunacci, 40, and Claudio Bugiantella, 45, were killed alongside two Franciscan friars on Friday when a second big quake struck while they were inspecting the damage to the 13th century pink stone church from an earlier tremor. Bugiantella was buried on Sunday morning in the nearby village of Petrignano. Brunacci was being buried in Assisi after an open-air service later in the day. The two friars, Father Angelo Api, 48, and 24-year-old Polish novice Borowec Zazislaw, were to be buried in the Basilica grounds on Monday. Luciana Brunacci, the surveyor`s widow, and sister Antonella Petrucci, demanded an official explanation of why the men were sent to the scene while tremors were still rocking the area. Seismologists said more than 200 aftershocks rippled through the Umbria and Marche regions after Friday`s quakes, which came nine hours apart and measured 5.5 and 5.6 on the Richter scale. Dramatic television footage filmed by a cameraman allowed into the basilica captured the moment the second quake hit and two chunks of the vaulted, frescoed ceiling caved in, raining down rubble and sending up a cloud of smoke like an bomb. Two priceless frescoes, one attributed to Cimabue and the other to the school of Giotto, were badly damaged but the most famous works, 14th century frescoes painted by Giotto on the side walls, survived cracked but largely intact. Art experts began the daunting task on Saturday of sifting through the piles of debris to piece the frescoes back together, but they said they thought it would be nearly impossible. Prime Minister Romano Prodi declared the earthquakes, which also affected many other towns in the region, a huge blow to Italy`s cultural heritage. A total of 11 people died in the twin quakes, three of them from heart attacks, civil protection officials said.