Windows 15 miles from the site were shattered and the explosions were heard in France
A memorial to the victims of the "worst recorded accident" in Britain's explosives industry has been upgraded to Grade 2* listed.
The upgrading - coinciding with the 100 year anniversary - offers greater protection and marks its significance.
At least 108 men and boys were killed at the Explosives Loading Company near Faversham in Kent on 2 April 1916.
A fire broke out in a wooden shed, igniting 15 tons of TNT and 150 tons of ammonium nitrate.
The explosions that followed shattered windows 15 miles away and were heard in France, Historic England said.
However, government censorship and a press blackout - for fear of alerting the enemy - meant the disaster was barely-reported at the time.
Mass grave
A memorial will be held at Love Lane on Saturday in memory of those who lost their lives
The majority of the victims, many of whom could not be identified, were buried in a mass grave in Faversham's Love Lane cemetery, where the memorial stands.
All the victims were male as no women worked in the plant at weekends - the oldest was 61 the youngest 17 - Historic England said.
The accident devastated the local community but was barely-reported at the time
Included in the dead, was the whole of the Works Fire Brigade, the Faversham Society said
Categories of listing
Grade I buildings - only 2.5% - are of "exceptional interest"
Grade II* buildings - 5.5% - are "particularly important buildings of more than special interest"
Grade II buildings are of special interest; 92% of all listed buildings are in this class
Historic England said: "The memorial is an eloquent and poignant reminder of the tragic impact of world events on this local community, and the sacrifice it made in World War One. "
It has pledged to list a total of 2,500 war memorials by 2018, marking the centenary of the war.
Culture Secretary John Whittingdale said: "Over a million Britons lost their lives in the First World War. It's important that their sacrifice is not forgotten."
