Updated

Police in Brazil's biggest city say a construction accident on a monorail meant to expand the city's metro network has killed a worker.

The victim was hit by a large concrete support beam that fell while being erected. An investigation into the cause of the accident is underway.

The accident comes as a strike has paralyzed Sao Paulo's subway system just before the city is set to host the opening match of the World Cup. It occurred near Brazil's busiest domestic airport of Congonhas.

Originally, the expansion of the metro system was meant to be completed before the World Cup to help fans move around the congested city. But in 2011, just a year after construction began, the government already warned it wouldn't be ready in time for the Cup.