Investigations are under way into how a section of pavement in Birmingham collapsed.

A piece of pavement in Corporation Street caved in on Saturday afternoon and a section of the road was sealed off, causing traffic chaos.

The collapse happened where a subway had been filled in to make the street more pedestrian-friendly.

Street-level crossings have replaced dozens of underpasses across the city because of safety fears for people using them, particularly at night.

The pavement in Corporation Street collapsed after subsoil was washed away by a leaking water main.

A passer-by noticed water bubbling up through the block-paving.

Shortly afterwards, a huge section of pavement caved in, to reveal water about ten feet deep filling the cellar of the Oxfam shop.

The shop was closed, along with Scrivens Opticians and the Jacobs photo store.

Structural engineers were called in because of fears for scaffolding on the 50ft high office block above the shops.