Two years ago, a two-vehicle patrol set out from the OSCE’s special monitoring mission forward patrol base in Kadiivka, a Luhansk Oblast city of 75,000 people located 800 kilometers southeast of Kyiv.

In one of the vehicles were two monitoring officers – one from Germany and the other from the Czech Republic – and a medic, U.S. citizen Joseph Stone.

Their patrol plan envisaged time monitoring the security situation around Pryshyb, a village close to the contact line in an area of Luhansk Oblast not controlled by the government. In so many ways, it was a regular OSCE SMM patrol. But, as the unfolding day would sadly show, it was far from regular.

At 11:17 a.m., on a dirt road near Pryshyb, one of the armored vehicles hit what appears to have been an anti-tank mine, throwing it into the air and setting it on fire. The two monitoring officers emerged from the vehicle miraculously alive, although with injuries. Joseph Stone died at the scene.

Of all those who had perished in the conflict in eastern Ukraine – and of the many more who would subsequently die – Joseph was unique in one important respect. He had come here as part of an international monitoring mission mandated to help restore stability and security, and specifically in the east, to monitor and verify compliance with various clauses of a ceasefire agreement. He, like 1,300 other colleagues of his in the OSCE SMM, chose this line of work, seeing in it an opportunity to do good and specifically in Ukraine to help restore peace to a long-suffering people.

Joseph’s death reflects a much wider and sadly ongoing tragedy. He will always be to those of us who worked with him a helpful trusted colleague into whose hands we willingly placed our lives. To his family, he will always be a loving and caring father, brother, and son. The open wound and empty space felt in so many of our hearts is sadly not unique. All across eastern Ukraine, there are fathers and mothers, sons and daughters, and brothers and sisters, missing, gone forever. In towns and villages – especially in places close to the contact line – there are empty seats in classrooms and playground swings are still, where once healthy joyous children learned and played. In one town, in Yenakiieve in Donetsk region, there is a home where three young brothers once lived. They, like eight other children killed since the beginning of 2016, died, just like Joseph Stone, because their roads, playgrounds and farms are littered with mines and other explosive remnants of war.

Those mines and unexploded ordinance are there despite the fact that there is a signed agreement to either remove or clearly demarcate them and not to plant anymore. That agreement dates back to September 2014 and was followed by a similar commitment in 2016.

We in the OSCE SMM have no higher priority than the safety and security of our monitoring officers. An array of security mitigation measures are taken on a daily basis and are adapted to ever-changing circumstances, especially so in light of the tragedy near Pryshyb. Training, equipment, planning, and information-sharing are but some of the ways in which we mitigate risks. Our presence in an often dangerous and volatile environment sadly means we can never fully avoid them.

Others too have responsibilities. The signatories of the Minsk agreements have undertaken to ensure the safety and security of SMM civilian monitoring officers.

Two years on – with another 56 innocent civilians dead and 158 more injured from mines and unexploded ordnance since that awful day in Pryshyb – and little has changed. For two years – in fact for almost five years – we in the OSCE SMM have been calling for just one very simple thing: that commitments made be honored. Surely, the time has come – in fact it is well past the time – when actions follow words; when mines are removed, especially in residential areas and other places frequented by civilians, allowing children to play and learn, farmers to graze their livestock, and people, including brave unarmed civilian monitoring officers and medics, to go about their daily business in safety.

It is a simple demand made by millions of mothers and fathers, and sons and daughters. Some steps have been taken – especially in terms of humanitarian demining – and many actors, including the OSCE SMM, are providing much needed mine-awareness education and outreach, in particular to the youngest and most vulnerable. Ultimately though full compliance with commitments made in the form of complete demining is urgently required. As well as saving lives and allowing for a return to normalization, this, and only this will be the lasting and fitting legacy to the hundreds of innocents who have paid the ultimate price, including one dedicated brave medic by the name of Joseph Stone. He and they will not be forgotten. May they all rest in peace and may their sacrifices and those of their families not have been in vain.