Friends of Malaysia Airlines Victims Describe the 'Vast Emptiness' After Crash

By Joanne Fowler

updated 07/24/2014 at 02:55 PM EDT

•originally published 07/24/2014 02:55PM

A week after Malaysia Airlines Flight 17 was brought down by a missile attack, friends and family members struggle to make sense of the tragedy and make sure their loved ones are not forgotten.

Colleagues of Dutch website director Antoine van Veldhuizen, who died alongside his entire family – his wife, Simone, 41, their two sons, Quint, 7, and Pijke, 3, and mother-in-law, Christiene, 64 – set up a memorial on Facebook to pay tribute to their beloved co-worker.

"They have died in a disaster that should have never taken place, leaving a vast emptiness behind," wrote Mark Welling, founder of the Amsterdam-based Expatica and longtime colleague of Veldhuizen. "Antoine will never return, but he will always be part of the Expatica family, forever known as its most important, energetic, loyal, likable, committed, sympathetic, best member with the loudest laugh."

"He and his family had such a wonderful life ahead of them," Welling wrote.

The townspeople of Vleuten in central Holland honored siblings Frederique, 19, and Robert-Jan van Zijtveld, 20, with a silent march Saturday night. More than 800 people who had known them from school, sports teams or the local grocery store where they had part-time jobs, turned up to honor the hardworking teens.

"We wanted to show the world, and their parents specifically, just how loved they were," Sophie Edixhoven, Frederique's best friend since high school, tells PEOPLE.

RELATED: Parents Remember Malaysia Airlines Flight Attendant Who Switched Planes (VIDEO)

"Frederique and Robert-Jan were great people, who would not harm a fly," she says. "Frederique was so kind and gentle. She did volunteer work and helped organize trips for children in Poland who could not afford to go on holiday."

The teens were en route to Borneo, Indonesia, with their grandparents, who treated the siblings to a special vacation in recognition of their success at school.

Emma Blanchard also lost her best friend, Tamara Ernst, 34, when the commercial airliner was shot down July 17. She and Ernst, a program manager at the Dutch sports company Zwolle, had become friends as members of a traveling club for singles years ago. "I noticed right away how social, kind and sweet she was," says Blanchard, 31. "She was one of the most fun people I have ever met."

"Every morning we sent each other a 'Good morning!' message on WhatsApp," Blanchard says. "We'd start joking until one or both of us broke out into laughter."

"It was the worst moment of my life when I heard that Tamara was on that plane."

• Reporting by Franka Hummels and Maaike Ruepert