BADALONA, Spain (Reuters) - Flames ripped through an abandoned warehouse occupied by scores of migrant squatters in a Barcelona suburb, killing at least three people and throwing a spotlight on the dire living conditions of Spain’s undocumented migrants. The fire, which broke out late on Wednesday sending a huge cloud of smoke into the air, was under control by Thursday morning but authorities said parts of the building had collapsed and there was a risk the whole structure could fall. Many people who were sleeping inside managed to escape but it was unclear if anyone else remained trapped inside, Catalonia’s acting regional president Pere Aragones said. Undocumented migrants often slept in the warehouse in the large industrial suburb of Badalona, Aragones said. The building had housed as many as 180 people in the past, a regional government spokesman said. Local resident Calixto Palomares, 71, told Reuters how he looked out of the window of his house and saw the building engulfed in flames. Slideshow ( 5 images ) “We saw how some people jumped from the windows,” he said. Emergency services treated 23 people, including three in a critical state, officials said. Prime Minister Pedro Sanchez offered his condolences, identifying two of the dead as north Africans. A group of African immigrants held a protest on Thursday in Badalona over their living conditions, holding banners that read “Black lives matter” and “We want a decent life”. An investigation would be launched into how the fire started, regional councillor Miquel Samper told reporters at the site on Thursday.