Workers are seen in the roof as construction continues at the Arena Amazonia on December 10, 2013 in Manaus, Brazil. The stadium will host matches during the 2014 FIFA World Cup Brazil. - 

Less than five months before Brazil's World Cup kicks off, 6 out of 12 venues are still unfinished -- including a complex in the northern city of Manaus, where construction workers have died and pay for laborers is an issue. Fifa has warned Brazil's World Cup 2014 host city of Curitiba that it could be excluded unless work speeds up. The BBC's Wyre Davies visited the sites of some of the World Cup facilities in Manaus. Click the audio player above to listen to the story.