Commuters were hit with delays of more than two hours after part of the District line ground to a halt.
Tube services stopped running along most of the westbound line after a person fell ill on a train at Whitechapel leaving some passengers stranded on trains which were at a standstill.
Transport for London warned of severe delays from Upminster to Richmond and Ealing Broadway lasting for several hours on Monday morning.
One train was taken out of service at Whitechapel, but a technical fault with the doors as people were getting off left many passengers trapped inside the carriages for another 10 minutes.
Luke Harper called the service “shambolic” after claiming he was forced to wait at Victoria station for a District line train for half an hour.
Fellow commuter Melanie Haslam, who was travelling from east London, said she could have flown abroad in the time it took her to get to work on Monday.
She said on Twitter: “Great start to the week.
“The agony of it taking me 50 minutes to travel 6 stops on the District Line.”
She added later: “I have finally made it into work! It only took me 2 hours. I could have flown to Majorca in that time.”
Sophie Bland said on Twitter she travelled two stops from Hornchurch to Dagenham East in 30 minutes after boarding the Tube at 8.09am.
Several others complained of being held up on their way to work.
Michael Izzard said online: “It would be quicker getting to Mordor than to work today.”
Can't believe I've been on the @districtline for 35 minutes and only moved 3 stops 😳😤😤😤😤😤— Rianne Byott (@Riannebyott_) March 20, 2017
@districtline person taken ill at Whitechapel, same train has door problems then everyone at Plaistow gets kicked off. Disgraceful— Jed Watson (@jed_w) March 20, 2017
@districtline absolute shambles of a at Whitechapel right now. Train kept on platform for over 20 mins 1/2— craig o (@nicegorilla) March 20, 2017
The District Line Twitter account said there had been two incidents. Someone had been taken ill on a train and then the same train developed a fault.
Severe delays btwn Upminster and Richmond / Ealing Broadway westbound. Tickets valid on buses and c2c. To re-plan https://t.co/RWol6vIzeh— District line (@districtline) March 20, 2017
TfL told the Standard they were sorry for the disruption.
At around 10am the District line spokesperson said the "earlier issue has now been resolved" but warned platforms may still be busy.