(AP) — Investigators are still trying to find the cause of a large brush fire near Salt Creek in Lincoln.

The fire on Saturday scorched a large area between the Salt Creek Levy Trial, a line of train tracks to the west, and West A and South streets. Fire investigator Don Gross said authorities have ruled out a passing train.

Firefighters say the blaze could have caused millions of dollars in structural damage, but crews were aided by off-duty firefighters and volunteers. Fire damage to foam board, shingles, trucks and a trailer at White Castle Roofing was expected to reach $200,000.

Gross says the fire appears to have started on a ridge, about 50 to 75 meters east of the train tracks.