Police investigating the deaths of two teenagers who were hit by a train are looking at the possibility they had been drinking or taking drugs.
British Transport Police are also trying to find out whether Stuart Adams, 15, and Lee Mullis, 14, were playing chicken dodging in front of trains with other youths.
The teenagers died instantly when the trans-Pennine express hit them about a mile north of Darlington station, County Durham, on Good Friday. It would have reached about 60mph by the time it reached the boys, having stopped at Darlington.
Mourners have left flowers under the Five Arches bridge, which takes the east coast main line over the river Skerne.
The accident happened at the northern end of the bridge, which is accessible only up a steep rise and by climbing a safety fence.
Police said the driver of the 18.10 Manchester Airport to Newcastle service saw the boys, but did not have time to brake. He informed police after the collision.
A spokesman said: "Inquiries are on going and we are still waiting to hear from coroner before formal identification can take place."