Sections of a building which was once the entrance to Sunderland's shipyards has been lost in a blaze.
Rooms inside the Doxford's West shipyard gatehouse, in Woodbine Terrace, Pallion, have been left severely damage by the fire, which also claimed wooden stairs inside the structure.
Tyne and Wear Fire and Rescue Service has said the cause of the fire is believed to be malicious, with the inquiry left in the hands of police.
Firefighters from Sunderland Central and North Moor fire stations were called to the site, near to the Sunderland Wall climbing centre, to find the fire had taken hold on the ground floor and first floor of the building.
Officers wearing breathing apparatus were sent in and used a hose reel to put out the fire, with a extension ladder also used in the call out.
Other areas of the building were damaged by smoke.
The building is at the centre of a campaign to preserve it for future generations, as Sunderland City Council has plans to build a dual carriageway as part of the third stage of Sunderland's Strategic Transport Corridor (SSTC) to link the New Wear Crossing with with city centre and the Port of Sunderland.
The council has plans and a budget in place to save the gates and archway and move those to a new location.
It says it recognises the importance of its heritage but that it is in a poor condition and cannot justify the funds to save it in its entirety.
In September, the council published a series of Compulsory Purchase Orders as it worked to clear the way for the new road.
They included one for the gateway building.
A planning application, including plans to relocate the gates, was approved last month.
At that stage, Councillor Michael Mordey, cabinet member for city services, said: "The City Council is very aware of our shipbuilding and industrial heritage and how proud people are of it.
"In our award winning Keel Square we’ve commemorated this heritage, the Vaux Site development is also commemorating shipping memories with The Launch.
"Discussions with the Doxford Engine Friends Association about the Doxford West Gateway have been on-going since 2015.
"As part of the SSTC works there are plans for restoring and re-locating its arches and gates alongside the new route as public art and a memorial to our shipbuilding heritage.
"The old foundation stone of the Crown Works has also been recovered and will be restored close to its original location."
A new western entrance into the Pallion Shipyard site features in the road scheme, with plans for a commemorative wall in recognition of the Crown Works also submitted to the council's planning department.
Campaigners have said they would like to see the whole gatehouse structure preserved, with the Save Doxford’s West Gateway Facebook page and a petition set up by supporters.
The fire happened yesterday at 3pm.
Anyone with information about the fire can contact Northumbria Police on 101 or Crimestoppers anonymously on 0800 555 111.