A 20 metre stretch of canal wall in central Amsterdam collapsed into the water on Tuesday, but no-one was hurt, eyewitnesses said.

It took about a minute for the pavement, including a lamppost, to sink, Robin Gouswaard, who was walking on the other side of the water, told local broadcaster NH Nieuws.

The Grimburgwal is home to the history of art and psychology departments of the University of Amsterdam. Everyone was able to leave the building safely, a university spokesman told the Parool.

⚠️ Eerste werkdag, stort ineens mijn kantoorgebouw in! HELP @UvA_Humanities @UvA_Amsterdam pic.twitter.com/7FMsSoMBvq

— Romy Beck (@beckromy) September 1, 2020

Engineers are now working to shore up the rest of the wall and assess the extent of the damage.

In July an official report for Amsterdam city council said that many of the bridges and canal walls in the old city are in poor state of repair. Several other have collapsed in recent years and some 20 locations in the city centre have been closed to heavy traffic.

City infrastructure chief Sharon Dijksma has commissioned research into some 100 kilometres of canal walls to find out how much work needs to be done. The city has set aside €300m for repairs but some the final cost could be as much as €2bn.

Dijksma told the Parool in a reaction to Tuesday’s incident that ‘this could happen in other parts of Amsterdam. It illustrates the importance of what we are working on.’