Commuters faced severe delays at Liverpool Street station during rush hour after a faulty train caused havoc.
A number of trains were cancelled or delayed on Monday evening after two busy lines were completely shut at the transport hub.
Photos posted on social media showed the packed concourse while passengers also complained of being stuck on crowded trains.
Engineers were working into the evening to fix the problem as commuters battled to get home on another sweltering day in London.
Greater Anglia said on Twitter: “A train from our depot at Ilford has broken down whilst departing from the depot
“As a result the two lines mostly used by TfL Rail services between Liverpool Street and Gidea Park / Shenfield are blocked between Ilford and Gidea Park.”
TfL Rail tweeted: “Severe delays between Liverpool Street and Shenfield while we fix a faulty train at Ilford.”
London Overground has also warned of severe delays between Liverpool Street and Edmonton Green due to the faulty train.
