Thousands of protesters gathered in early October at a landmark Paris tower once lined with asbestos to demand a nationwide lawsuit against those who allowed workers to be exposed to the hazardous substance.

Relatives of workers who died or suffer from asbestos-linked lung ailments led the march from Montparnasse Tower toward the Health Ministry. Some 3,100 people from around France took part, according to police. Many carried photos of deceased family members, under a banner reading, “Our poisoners must be prosecuted without delay.”

The protesters were demanding a large-scale lawsuit that would draw nationwide attention to the consequences of asbestos exposure. Organisers said 3,000 people in France die each year from asbestos-related disease, though no official numbers are available. Asbestos was systematically used in French buildings and manufacturing into the 1970s, and was only formally banned in 1997.