GEOFF BENNETT: Welcome to the "NewsHour."

Russian opposition leader Alexei Navalny was buried today on the outskirts of Moscow two weeks after his sudden death in a Siberian prison camp.

AMNA NAWAZ: He was mourned by thousands in the streets amid threats by the Kremlin and a massive police presence.

With his mother and father by his casket, but with his wife and children outside of Russia, Navalny showed, in death, he could still conjure resistance to Putin's authoritarian rule.

Nick Schifrin begins our coverage.

NICK SCHIFRIN: Alexei Navalny dreamed of a Russia that was free, its citizens unafraid.

And, today, thousands, perhaps tens of thousands, braved arrest to thank the man who helped them replace fear of the state with faith in themselves.

They chant: "Russia will be free.

Putin is a murderer.

No to war."

WOMAN (through translator): We couldn't not come.

Let them see that many remember, many know.

Silencing won't work.

NICK SCHIFRIN: And yet today was also a reminder of the fate that befalls the Kremlin's opponents, Navalny's open casket, overseen by his parents, removed quickly before everyone could say goodbye.

But even in his last moments above ground, in his last rites, as the priests covered his face, Navalny did it his way.

The orchestra played Frank Sinatra's "My Way" the moment he was buried and, after, the theme song to "Terminate 2," whose primary message is, the future is not yet written.

And that perhaps is Navalny's legacy, reminding Russians their fate hasn't been decided and that politics requires participation and the will to fight.

Today, the risk of arrest was real.

Police detained dozens of Navalny supporters across the country.

And before the funeral, Kremlin spokesman Dmitry Peskov warned this: DMITRY PESKOV, Spokesman for Vladimir Putin (through translator): Any unauthorized gatherings will be in violation of the law, and those who participate in them will be held accountable.

NICK SCHIFRIN: In Russia's system, Navalny was the equivalent of a terrorist leader, sentenced to decades in prison for extremism.

He died in a penal colony of what authorities called natural causes.

His wife, Yulia, said he was murdered.

YULIA NAVALNAYA, Widow of Alexei Navalny: Alexei was tortured for three years.

He was starved in a tiny stone cell, cut off from the outside world and denied visits, phone calls, and then even letters.

And then they killed him.

NICK SCHIFRIN: Today, Yulia Navalnaya posted this video tribute, a love letter to a love song, a wife who's lost her husband, a Russian opposition who's lost its leader.

Navalny always knew he could be silenced.

He wasn't afraid of that either.

ALEXEI NAVALNY, Russian Opposition Leader: My message for the situation when I'm killed is very simple, not give up.

NICK SCHIFRIN: And so, today, they didn't.

"Navalny might have been imprisoned," one attendee said today, "but he died a free man."

For the "PBS NewsHour," I'm Nick Schifrin.