French President Emmanuel Macron was met with a wave of protests in 2018 when he tried to raise the retirement age. Now he is trying again, despite warnings that Thursday would be a "hellish" day.
Teachers, healthcare workers and railway staff were among more than a million people who demonstrated in rallies nationwide. They are angry over Macron's plan to raise the age at which they can qualify for a full pension from 62 to 64.
Their walkouts stopped trains, closed schools, and even disrupted the flow of electricity.
One rail worker said, "It is a social issue. Do you want to retire sick, broken, or even dead?"
France spends more than most countries on pensions, amounting to nearly 14 percent of gross domestic product.
Macron said, "If you want the pact between generations to be fair, this reform needs to be carried out."
Police used tear gas to disperse the crowds and detained some of the protestors. However, union leaders say the demonstrations are just the beginning.