Flames engulfed the building that houses the YMCA in Thessaloniki yesterday afternoon, completely destroying the roof and its theater. Authorities said that 70 firefighters using 18 trucks were involved in the operation to put out the fire that broke out about 6.30 p.m. They described the operation as being difficult due to the age of the building and its complex structure. Thessaloniki Mayor Vassilis Papageorgopoulos said that the blaze did not destroy the YMCA’s library or storage files. Authorities launched an investigation into the causes of the fire.