A burst water main in the centre of Glasgow caused flooding and led to morning rush-hour delays.
Police were called to the A81 Garscube Road, near Raglan Street, at about 0715 BST after reports of up to 18ins (45cm) water.
A new pedestrian underpass which was due to open to the public later has been completely flooded.
Surrounding roads were closed with diversions in place. One passer-by said the water had caused "real chaos".
He told the BBC Scotland news website there was "streaming torrents of water" on Garscube Road.
The driver of one car had to abandon it after it got swept off an approach ramp to the M8.
Workers at the new Cowcaddens underpass said it had been filled with about 10ft (3m) of water.
The underpass is part of the "Phoenix Flowers" regeneration project set up by Glasgow City Council and British Waterways.
Street lights in the style of pink, orange and yellow flowers have been erected linking the walkway to the Forth and Clyde Canal at Speirs Locks.
A spokeswoman for Glasgow City Council said a "soft opening" had been planned for this week, with the official opening of the project due to take place on 28 June.
She added they would have to wait until the water subsided before they could assess the extent of the damage.
Cowcaddens underground station was shut for two hours but has now reopened.
The flooding also affected junction 17 on the M8 and New City Road westbound was closed.
One resident on Garscube Road said water had been leaking on to the roadway for a "considerable time" and that Scottish Water had been contaced several times by local people.
Scottish Water said a 36in-diameter trunk main had burst in the Garscube Road area.
A spokesman said workers were making progress in tackling the burst.
A second major burst also caused traffic problems in the east end of the city, on Alexandra Parade.
The pipes are two of the major mains that supply water from the Milngavie Water Treatment Works to Glasgow.
There were also a small number of related bursts in areas such as Boran Street, Port Dundas and Newhall Street, Shawfield.
About 70,000 properties in the city were left without water or experienced lower than normal pressure, although most have now had their supplies restored.
The cause of the bursts was related to an automatic valve which failed to operate and caused higher than normal pressures in the system.
The spokesman added: "We would like to apologise for any inconvenience and thank customers for their patience."