The victims were the Swiss owner of the house under construction, and two South American workmen.
The powerful explosion, which threw debris and glass to distances of metres around the property happened at 12.30pm yesterday at No. 24, Calle Sud.
Neither the owner or workers had been alerted to the fact that there was a gas leak in the basement which had been accumulating in strength.
The workers were working with polyurethane and had lit a gas tank, when suddenly a huge explosion shook the house. Some wall and roof structures were sent flying through the air, whilst the three men were left seriously burned.
The alarm was raised by neighbours, who had been startled by what they thought had been a bomb going off, and Emergency services - firemen, Guardia Civil and paramedics - rushed to Cala Llombards.
The distraught men were found with extensive burns over large areas of their bodies, especially one of the South American workers whose body was 80 percent burned.
After being treated on the spot, the victims were ferried to Son Espases hospital in Palma. Local Police and Guardia Civil began an investigation into the causes of the explosion whilst technical explosives experts checked to see whether there was any remaining risk. Two air ambulances were mobilised, one of them from Minorca, in case the need rose to take the most seriously injured victims to the Vall d'Hebron hospital in Barcelona.
Medical sources consulted said that the state of health of all three men remained very delicate.