Tear gas fills the streets of Zurich during riots on June 18, 1980.
Photographer Olivia Heussler was standing on the roof of a building next to the Zurich police officer in charge of coordinating action on the ground when this shot was taken in August 1980.
Tear gas canisters hiss on the streets in an attempt to stop the demonstration.
After a demonstration on August 1, 1980, Switzerland's national holiday, protesters cooled off in the river.
Nearly 125 people were arrested during the protests. Here, Heinrichstrasse is littered with items used for barricades during a 12-hour-long demonstration.
Police hold their line after protesters staged a sit-in before city government buildings.
When Zurich was "like a warzone".
A growing frustration among youth throughout the 1970s at a lack of public funding and work space for a new generation of musicians, actors and artists eventually led to months of riots and clashes with police in Zurich's normally orderly streets.