Ministry of Social Development staff and members of the Ashburton community have marked a year since the deadly shooting that killed two workers.
Peggy Noble and Leigh Cleveland were killed when a gunman opened fire in their office while Lindy Curtis, who was shot in the leg, was seriously injured.
Ministry of Social Development staff laid wreaths at 10.52am at the former Work and Income office in Ashburton, to commemorate their deaths.
Ministry chief executive Brendan Boyle and associate Social Development Minister Jo Goodhew attended the ceremony, and Mr Boyle later said planning for an event as extreme as the shootings in Ashburton last year was almost impossible.
"Apart from the awful shock on the day, it made us clearly look really closely at our security arrangements," he said.
"We had thought, as many organisations do, that that is kind of the worst thing that could happen.
"In reality, it's almost impossible to be able to put those protective measures in place for an event as extreme as that but we've been very clear, especially since that event, that we will not tolerate threats."
Police had issued trespass notices to more than 400 people banning them from Work and Income offices in the past year.
About 50 members of the community were at today's service; some comforted each other after the short memorial.
Ministry staff nationwide observed two minutes silence at 9.52am, the time that the shootings happened.
The Ashburton Work and Income office has since relocated and security at the branch has been increased.
Russell John Tully is charged with murdering Peggy Noble and Leigh Cleveland and the attempted murder of two of their colleagues, Lindy Curtis and Kim Adams.
The accused also faces two firearms charges and one of setting a trap police say was intended to injure people.
The trial was due to begin in May but was delayed and a new trial date has yet to be set.