The mother of an Irishman killed in the Ethiopian Airlines plane crash has said her son "wanted to save the world".
UN aid worker and engineer Michael Ryan was killed when the plane crashed shortly after take-off from Addis Ababa on Sunday morning.
"He's an amazing person. We can't believe it and we can't come to terms with this. His wife and children are just devastated," Mr Ryan's mother Christine said.
"He was a very enthusiastic person. He had a great vision and he believed in engineering and in putting people first."
Mr Ryan was employed by the UN's World Food Programme (WFP), a humanitarian organisation delivering food assistance in emergencies and working with impoverished communities to improve nutrition.
The married father-of-two, originally from Lahinch in Co Clare, had relocated to Rome to work at WFP headquarters.
His wife Naoise and children were due to move out to Rome in the coming months.
The plane was en route from the Ethiopian capital Addis Ababa to Nairobi and crashed on the eve of a UN Environment Assembly in the Kenyan capital.
Several WFP staff were on the flight. Mr Ryan was a global deputy chief engineer with the WFP's engineering division.
Mrs Ryan said she knew her son was flying to Nairobi, but didn't know he was on the crashed jet until his wife contacted her.
"Naoise was saying that she was always concerned when he got on different flights, but when he got on this particular flight she wasn't particularly concerned as he had been in worse situations and survived and got through it," she added.
"He was involved in a lot of projects worldwide: flood relief, landslides, Ebola. He had been in Afghanistan, Pakistan and Sudan.
"He felt he made a difference. He had a marvellous vision and he just got there and did it and had great enthusiasm.
"He always wanted to help others. He loved people and would light up a room. He never wanted a nine-to-five job, he put everything into his work. He had some amazing stories.
"There was a lot of danger for him, but he loved his work."
Mrs Ryan said her son was turning 40 at the end of the month and the family were to fly to Rome next week for the celebrations.
President Michael D Higgins has also paid tribute to Mr Ryan.
"I wish to extend my deepest sympathies to the family of Michael Ryan, whose work in humanitarian assistance for the World Food Programme brought him on to the flight," he said.
"I send my deepest sympathies to President Sahle-Work Zewde, to the families of the victims, the people of Ethiopia, and the Ethiopian community who live here in Ireland."
Taoiseach Leo Varadkar expressed his sadness.
"I had the opportunity to visit Rome a couple of years ago to do some work with the WFP," he said.
"It's really important and honourable work and I am really sad for him and really sad for his family and his friends that his life has ended this way."
Flight 302 took off from the Ethiopian capital with passengers from more than 30 countries. The plane was making a rattling noise and trailed smoke and debris as it swerved above a field before hitting the ground, according to witnesses.
All on board the Boeing 737 died. Both the flight data recorder and cockpit voice recorder were recovered. The pilot had requested permission to return, saying he was having problems, but it was too late.
"It was a loud rattling sound, like straining and shaking metal," said Turn Buzuna, a farmer and housewife who lives about 300 metres from the crash site.
"Everyone says they have never heard that kind of sound from a plane," she added.
Malka Galato (47), a farmer whose field the plane crashed in, also described smoke and sparks from the back.
"The plane was very close to the ground and it made a turn. Cows that were grazing in the fields ran in panic," he said.
At the site, Red Cross workers sifted gently through victims' belongings, with debris spread over land roughly the size of two football fields.
Children's books - Dr Seuss's Oh The Thinks You Can Think and Anne Of Green Gables - lay near a French-English dictionary.
"When it was hovering, fire was following its tail, then it tried to lift its nose," said another witness, Gadisa Benti.
"When it passed over our house, the nose pointed down and the tail raised up.
"It went straight to the ground with its nose, then exploded."