What would he have made of it all, was the repeated refrain on social media. Would he, a champion of peace and tolerance recognize the capital city at all?

The burning rubber permeated the air down the length of the street named after the Liberator. 

It was there outside the GPO, where Christmas decorations and lights are festooned across the windows, oblivious to what had happened a few hours previously. 

Halfway up the thoroughfare sat a metal hulk, the remains of what was a double-decker bus, twisted and burnt as if it had been put through some kind of ringer. 

Beside it the stricken Luas train, windows smashed, doors stuck open, as if the carriages were evacuated quickly in the face of some natural disaster. A mobile crane was at work, trying to clear away the debris and get the city back in working order. 

Outside the garda tape, a scattering of early morning commuters stopped and raised their phones to snap a memento of the occasion.

Across the road Parnell Square East is still blocked off, a knot of gardaí standing at one end of the road. This is the primary crime scene, where the day’s horror began when a man stabbed children before being restrained.

Another immobile bus sits halfway up the square, as if it also is unable to move because of the shock. Up and down the street the cleaning machines were out humming through the dawn, getting the centre prepared for another day. 

It will be a long time before one of its darkest days in decades is forgotten.