Thousands of commuters suffered nightmare journeys to work today after a series of problems on the London Underground.
To make matters worse, all the difficulties affected the north west area of the capital, with passengers seeking to avoid delays on one Tube line then facing delays on other routes.
The worst problem was on the Metropolitan line where late-running engineering work meant there were no trains able to run between Harrow-on-the-Hill and Aldgate.
A late finish to engineering work on the Jubilee line led to a suspension of services in the rush-hour between Stanmore and Willesden Green, with severe delays on the rest of the line.
Passengers trying to get round the problems by switching to the Piccadilly line then ran into more problems, with a faulty train at Rayners Lane leading to severe delays between South Harrow and Uxbridge.
Intrepid travellers then tried their luck with London Overground or Bakerloo line services in north west London. But a signal failure at Queen's Park led to severe delays to Bakerloo services and also caused problems for Euston-bound London Overground trains.
London Underground chief operating officer Howard Collins said: "Engineering works to replace more than half a kilometre of track this weekend overran, which mean the Jubilee and the Metropolitan lines were part-suspended this morning.
"Our engineers are working flat-out to restore services as soon as possible and rail replacement buses are running. I would like to apologise to passengers who were affected by the delay in services. We will be carrying out a thorough investigation into what caused the works to overrun."
To add to a morning of upheaval on the Tube, the last part of the rush-hour was affected by a signal failure at Brixton in south London which led to delays on the Victoria line.