Tube trains on the Central Line are running again in east London after services were suspended when the track was flooded.
People had to be led off a train after a Thames Water pipe burst on Wednesday, causing flooding at Stratford station.
The Central Line, which was suspended between Bethnal Green and Leytonstone, was reopened at 16:40 BST on Thursday.
The water had got into a ventilation shaft and flooded a track. Thames Water apologised for the problems.
BBC London's transport correspondent Tom Edwards said about two million litres of water flooded the line.
Replacement buses were put on for people travelling along the route.
A spokesman for Thames Water said during the work: "We're really sorry for the disruption this is causing."