Four people were injured after a pedestrian bridge on the N3 highway in Germiston collapsed, Ekurhuleni metro police said on Wednesday.

The upgrades on parts of the M1 will cause traffic chaos, but the roads agency says they are vital to the country’s economic growth.

The first sitting of the inquiry has revealed that deadlines were missed, bolts were missing and concerns about alignment had been raised.

The construction firm’s project manager was unable to say what led to the collapse of the temporary structure last October.