About 2,000 people were evacuated and trains cancelled or delayed due to an electrical fire at London Paddington.
The station was cleared at 19:30 BST due to the fire in an intake room, which London Fire Brigade (LFB) tweeted to say had been put out at 22:00.
Passengers were later let back into the station to wait on the concourse.
Matt Willis, of Arriva Trains Wales, said on Twitter that some services had departed, including the 22:30 to Reading and the 22:45 to Swansea.
A Network Rail spokesman said platforms one to six had reopened.
He said the others would remained closed until firefighters gave the all-clear.
Gavin Fellows, 50, a cyber security consultant from Gloucester, criticised the lack of information.
"I've been waiting for two hours. I was told it was going to reopen at 9.30pm," he said.
"I was in the station when the alarm went off and it said 'emergency situation, please evacuate'. There hasn't been any communication. I'm not happy."
An LFB spokesman said firefighters left the scene after the fire burnt itself out.
Great Western Railway customers were advised to use Chiltern Railways, CrossCountry, South West Trains and London Underground.
