"Grey October" was written by Peggy Seeger and IIRC, Jack Warshaw, in 1966 after the Aberfan disaster. It compares, verse by verse, Aberfan with a primary school in Thuy Dan in Vietnam, bombed by US planes on the same day.
The last two verses:

"Tears are shed for Glamorgan children
And the world mourns Aberfan
But who will weep for the murdered children
Beneath the rubble of Thuy Dan.

Grey October in Glamorgan
Warm October In Vietnam
Where children die and we stand by
And shake the killer by the hand."

I still find this song difficult to sing for thinking of the children from both places.

Eddie