ScotRail’s flagship line will remain closed today after it was shut by a landslip.
The first such incident on the main Edinburgh-Glasgow route for 18 years saw the collapse of part of a wall onto tracks near Winchburgh in West Lothian.
The ScotRail Alliance with Network Rail stressed the remaining wall was safe.
However, it is not yet known whether it could have been weakened by the installation of a pylon adjacent to the landslip, which supports overhead wires as part of electrification of the line, which was completed in October.
ScotRail said the disruption was due to continue until the end of Thursday.
The landslip was the third to hit Scotland’s railways in three days, and came hours after the line was shut by dangerously high water levels under a nearby bridge.
Passengers were switched to buses between Linlithgow and Edinburgh Park or urged to switch to other lines Edinburgh-Glasgow lines.
However, one of them, via Airdrie, was also disrupted by flooding between Bathgate and Livingston North when a pump failed after tracks were engulfed with water.
The wall collapse also halted Dunblane-Edinburgh trains, with none running east of Falkirk Grahamston.
ScotRail tweeted: “Engineers are on site assessing the damage and putting plans in place to reopen the railway.
“Embankment needs to be inspected to ensure it’s safe to run trains. More than just shifting a few rocks involved.”
However, passengers expressed anger at the lack of information from ScotRail.
Máire Dobbin tweeted: “A bit of communication from @ScotRail in Linlithgow this morning would’ve been helpful, it was absolute chaos!”
Susan Murrin tweeted: “I was on 0730 from Ed-Queen St. On the same train for 2h45 mins – minimal info and no contact with on train staff.”
A ScotRail Alliance spokesman said: “We apologise to customers for any disruption and share their frustration. However, their safety is our number one priority.”
Elsewhere, a landslip at Kirkconnel shut the line between Kilmarnock and Dumfries and the A76 road.
The Fort William-Mallaig line is expected to open next Monday after a 1,000-tonne landslip on Monday.
A total of 26 flood warnings were in force last night, including in the Borders and Tayside.
The Scottish Environment Protection agency tweeted: “We’re starting to see river levels falling in some areas, but many of the larger rivers (Tweed, Clyde, Nith and Spey) will remain high into tomorrow [Thursday].”