What happened on Tuesday May 18, 1993?

Question

There is a song I've listened to called "Tuesday May 18th 1993" by Aus-Rotten and the lyrics are not enough to let me know what happened the day. Here they are if they're any clue:

A day in the life of a never ending war

the killing still continues for more than fifty years before

by the time the war has ended a new one's just begun

modern day is just the same no war is ever one

you'd think we'd learn our lesson

but it's so plain to see

same old fate with a brand new date

chalk up the casualties

[Chorus:]

as history repeats

tuesday may 18 1993

how many millions died

by 1945

they claimed never again

but the nightmare's still alive

[Chorus]

how many lives were lost

by the n**i holocaust

see history reappear

ethnic cleansing's here

[Chorus]

commoners kill eachother anotyher racial riot

ethnic cleansing is allright as long as it's kept quiet

the gods have called upon us to kill the hethen kind

The holocaust never happened excpet to the jews it left behind

ignorance has triumphed so its off to war again

color and culture we're all still ******* men

fashionable fascist *****

war is just for profit

it's all the same to them

they'll send over out children

and **** us once again

[Chorus]

Answer 1

Denmark ratified a treaty for European cooperation.

Answer 2

Eu riots in Copenhagen caused by the approval of the four Danish exceptions in the Maastricht Treaty referendum. Police opened fire against civilians for the first time since World War II and injured 11 demonstrators.