Hundreds of commuters were stuck on trains into London during rush hour following a trackside fire on Monday morning.
Trains to Paddington and Heathrow were stopped for around 90 minutes just after 6.30am and Network Rail said 70 journeys were cancelled.
Firefighters attended a rail-side blaze near Canal Way in North Kensington at 6.41am, London Fire Brigade (LFB) has said.
An LFB spokesperson said trackside switch equipment and trackside cabling were damaged by fire. There were no reports of any injuries.
Network Rail apologised for the disruption and warned passengers that reduced services will be running through the morning.
A spokesperson said: "Due to a lineside fire in the Ladbroke Grove area earlier this morning, services between Paddington and Maidenhead station were suspended at 6.38am.
"Services resumed just before 8am, though they may still be subject to residual delays.
"We apologise for the disruption caused to passengers' journeys this morning."
Routes run by Great Western Railway (GWR) and Transport for London (TfL) have also been affected.
TfL said trains started moving again around 8.30am but journeys between Paddington and Heathrow and Paddington and Reading are "severely delayed".
At least 12 GWR trains were cancelled and many more delayed, according to the operator's website.