Police are still looking to confirm the identities of two people, believed to be an adult and a child, killed on a train track during rush hour.
British Transport Police (BTP) said the deaths continue to be treated as "unexplained" and are looking to contact the next of kin.
They were unable to confirm whether the victims, struck by a train shortly after 6pm at Ealing Broadway in west London yesterday, were related.
A spokesman said: "We are still treating it as unexplained and are working to establish exactly the circumstances and their identities.
"We are keeping an open mind on the circumstances."
Emergency services were called to the scene at 6.10pm following reports that someone had been hit by a train.
Police have appealed for witnesses or anyone with information to come forward.
Heathrow Express services which were last night suspended have this morning returned to normal, the company said, while First Great Western said there were minor delays to some long-distance services.