The restoration of services on the central section of a London tube line suffered a last-minute hitch when it had to be suspended again because of a fire alert.
Trains will start running to some of London's busiest stations
From Thursday the Central Line once again began running through London's shopping centre and the financial district in the City.
But an hour after the service resumed it had to be halted for Fire Brigade safety checks at Tottenham Court Road station.
London Underground resumed services at 0820 BST, only to close the eastbound section from Marble Arch to Liverpool Street less than an hour later.
The stretch was closed for 45 minutes while a faulty train, which had developed an electrical problem, was removed.
Hundreds of thousands of commuters have been squeezing on to other services since the busy line was shut following the derailment at Chancery Lane station on 25 January.
Only a limited service is operating on the stretch between Marble Arch and Bethnal Green, bridging the gap between two shuttle services already operating at either end of the line.
Estimated cost of line suspension
£40m to London Underground
£25m to the City of London
15% fall in Oxford Street retail
It means a number of Central Line trains are running from Ealing Broadway, in the west, to Woodford, in the east, through busy central stations such as Bond Street, Oxford Street and Bank.
However the branch from West Ruislip and North Acton remains shut, as does the Essex 'Hainault loop' and the Woodford to Epping stretch - they are expected to open by Easter.
A full timetable will not be restored until after the Easter Bank Holiday when the last of the 85 trains are modified by safety experts.
The line was closed following an accident when a traction motor came loose underneath a train and fell on the track.
Dust was thrown up by the first trains through stations in 67 days
Trains have been fitted with safety brackets to catch motors, should they fall off again.
London Underground (LU) on Thursday denied accusations by the Rail Maritime and Transport (RMT) union that reopening the line before an inquiry into the derailment had been completed was unsafe.
Andy Byford, general manager of the Central Line, told BBC London 94.9 that he was assured passengers were not at risk.
"I do believe the trains are safe," he said.
'Huge' engineering task
"We have identified an engineering solution approved by our safety regulator.
"We know it's a safe solution. We would not be operating the line if it wasn't."
LU has faced questions from MPs and Transport Secretary Alistair Darling about why work to make the trains safe has taken so long.
Managing director Paul Godier admitted modifications and safety checks had taken longer than hoped because the scale of the engineering task had been "huge".