At the dawn of the 20th century, Russians made up a notable part of the working population in the biggest industrial cities. In Latvia, as in the rest of the Russian empire, the situation of factory workers was grim. They worked on average 11 hours a day, 10 on Saturday, and this under harsh and unsafe conditions. Social agitation built up over the course of several years; when workers protested at the Winter Palace, police and Cossacks attacked the procession, killing or wounding hundreds. This event marked the start of the Revolution of 1905.