METRO drivers had to be put on alert after grass was set on fire near train tracks.
Drifting smoke could have brought trains to a halt and now firefighters are warning about the dangers of starting fires.
A crew from Sunderland’s Central station were called to the blaze, near European Way in Pallion, at 4.45pm today.
They spent about 45 minutes bringing the 20-square metre area under control and issued a warning to Metro drivers passing through the area.
Watch manager Steve Errington believes arsonists were responsible for the fire and says the number of deliberate fires soar during school holidays.
He added: “It was quite a serious incident for a small grass fire, as we had to work on the embankment and we had to put procedures in place.
“We would have made closing the tracks a last resort.
“We thought about it, but it seemed better to put a warning out instead.”
Firefighters had already put out a similar fire near the Bunny Hill walk-in centre, which was reported at 12.30pm the same day.