Russia's full-scale invasion of Ukraine began four years ago today.

Europe's largest and most brutal conflict since the Second World War has claimed hundreds of thousands of lives, over 15,000 of them estimated to be civilians.

European leaders met again today to pressure Russia as the many rounds of peace talks over the last year have produced

few results, and as beleaguered Ukrainians struggle to deal with the war's terrible toll.

Nick Schifrin reports. And a warning, some images in this story are disturbing.

In Kiev this morning, a moment of silence for a nation in mourning.

Four years of war and sacrifice.

Of air raid sirens and cemeteries filled.

Four years of grief, of mothers who will never again see their children.

The ultimate sacrifice made by more than 100,000 Ukrainian soldiers.

As the hell of this war rages, the front lines become so deadly it's known as a

12-mile-wide valley of death. 1.6 million Russian Ukrainian soldiers have either been killed,

injured, or are missing since the start of the war. That number will reach 2 million this spring.

More than 60% are Russian.

It is usually illegal to enter Russian military cemeteries, but a woman posted this YouTube

video from St. Petersburg and a poem placed next to the grave of a 30-year-old Russian soldier.

No need to cry for me. So many of us are dying here.

Countless of us. The blood of boys is everywhere.

In Ukraine, it's been the deadliest year of the war. The targets include kindergarten,

one in Harkew, where parents and emergency workers ran to rescue 48 children who all survived.

Also, hospitals is patients rescued on stretchers, nursing homes, evicting the most vulnerable,

and entire cities.

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