By Humphrey Carter AS dawn broke yesterday, the true extent of Tuesday night's powerful gas blast which ripped through a ground floor flat in calle Ignasi Barranque, near the Palma conservatory of music, shocked neighbours and the local community. The blast, which injured three people, happened just after 9.30 pm when a butane gas bottle apparently exploded destroying the dining room and scullery and causing widespread damage to the rest of the property. Yesterday fire chiefs said a large part of the flat is going to have to be demolished while structural engineers continued inspecting the entire block of flats to make sure it is safe. The ground floor duplex-property was home to Rafael Carceller Albert his wife Trinidad Cornejo Romero and his elderly grandmother. The grandmother and Rafael both suffered minor injuries and were discharged from hospital yesterday afternoon but Trinidad was yesterday airlifted from Son Dureta Hospital to the Vall d'Hebron burns unit in Barcelona to be treated for burns to 80 percent of her body. The exact cause of the explosion has yet to be confirmed but fire chiefs suspect it was caused by a gas leak in the basement. Fire fighters and the Local Police evacuated the whole block. Yesterday the blast area was cordoned off with residents staying in alternative accommodation until they are given the green light to return to their homes.