Major disruption to rail services is expected to last a week after a bridge wall collapsed near the scene of a fatal train crash in Aberdeenshire.
The stone structure fell away on Friday, about a mile away from where three people died in a rail incident in August.
The line between Montrose and Stonehaven is closed while Network Rail teams assess the situation.
A spokesperson for Network Rail said: “We’re making good progress in assessing the damage to the bridge parapet, but the height of the structure and rural location make this a complex job to carry out safely.
“Assessment of the bridge continues over the coming days as we plan its repair.
“The line will remain closed this week and we’ll provide more updates when we have them.
“We’ll work around-the-clock to reopen the line quickly and safely for passenger and freight services.”
Structural engineers were inspecting the site to plan for repairs at the weekend, but the line is expected to remain closed throughout the week.
ScotRail is running replacement transport between Stonehaven and Montrose, connecting services at either side of the closed line.
The Dundee to Aberdeen railway line only reopened in November, having been closed for almost three months following the derailment of a train near Stonehaven in August.
A passenger, conductor and the driver died when the Aberdeen to Glasgow service came off the tracks on August 12 following heavy rain.
An interim report published in September said the train hit washed-out rocks and gravel.