An Irish aid worker has told how the brutal beheading of Scot David Haines was like a "bolt" hitting his colleagues in Iraq where he is currently based.
Dubliner William Holden (44), from Clondalkin, Dublin, is in the city of Erbil, the capital of Kurdistan.
He has been continuing the vital work he has been doing since earlier this year as head of logistics and procurement with the Danish Refugee Council.
"The last few weeks have been yet another roller coaster. Just when things seem to settle, for a day or two at least, the horrors rise up once again and grab your full attention," William told the Herald.
He said that David Haines was personally known to some of his colleagues in the non-governmental organisation sector in Iraq, even though he was kidnapped in northern Syria.
"While we hear countless tales of heart-breaking loss from the families that we come into contact with while distributing food, water, kitchen utensils, it was like a bolt hitting us when we heard of David's death. He was one of us," William said.
"Even though we have tightened up our security protocols piece by piece over the last three months we are doing so again.
"Making sure that the doors are locked at night, the car is outside ready to go, additional security cameras and tracking devices and so on," William told the Herald.
A video emerged last Saturday night of the murder of dad-of-two Mr Haines (44).
He was the third hostage to be killed by Islamic State terrorists, following the murders of American journalists James Foley and Steven Sotloff.
William said that he is continuing with his work.
"Just last week I returned to Baghdad in order to follow up on the purchasing of food, for about 2,000 families in the cities of Ba'quba and Ramedi," he added.
In Ramedi, the ordinary people are really struggling, the Dubliner said.
"I heard that they have not had any medicines replenished for months and basic ailments such as asthma and diabetes are deadly.
"Ramedi is about the same driving distance, on a normal day as it takes to drive from Dublin city centre to Athlone.
"Yet that journey now takes anything between 12 and 18 hours due to the security checkpoints and detours that you need to take to steer clear of the fighting," he said.
He will be returning home for a visit in four weeks time.
"The work we do hopefully will make a small difference."