The police officer in charge of the Pike River mine rescue mission has given emotional testimony to the inquiry into the disaster.
Superintendent Gary Knowles described the families' switch from elation to what he called an outpouring of grief.
A Royal Commission is inquiring into the disaster that killed 29 men in the West Coast coal mine last year.
During a long period on the stand before the Commissioners in Greymouth on Wednesday, Superintendent Knowles broke down in tears as he described what he called the worst day in 34 years of policing.
Superintendent Knowles took operational charge of emergency services after explosions last November.
He told Commissioners he was forced to tell relatives of the trapped men that they had definitely died after a second massive explosion at the mine.
Unfortunately the mine manager had earlier told the families a rescue mission was planned but their applause turned to horror when Superintendent Knowles was forced to intervene and give the bad news.
He said the prospect of telling them any hope had gone was dreadful.
He told the Royal Commission he still had memories of that day and he formally apologised to the families for the way in which it was handled.
A spokesperson for the bereaved relatives, Bernie Monk, issued a statement later, saying he accepts the apology, adding the police are human beings.
No challenge to police role - Knowles
Earlier in the day, Superintendent Knowles, the Tasman Police District Commander, told Commissioners the police were never challenged in their decision to take control of emergency teams.
This contrasts with comments made by others to the inquiry. Opinion covered so far has suggested the police should never have taken control of the operation but should have left this role to experts in mining and mines rescue.
Superintendent Knowles said the police taking charge matched general practice. He also rejected suggestions the police should have authorised sealing off the mine, saying neither the mine company nor the Department of Labour wanted that.
"At no times was I or other police officers challenged by anyone as to who was the lead agency. No-one from any other agencies ever suggested that another agency was better qualified at that time to step up and take command of the situation," he said.
"Furthermore, I'm not aware of any other police officer, including myself, in the time I was on Operation Pike who's been challenged in relation to that role."
He said the pattern of the police controlling incidents with a technical component, such as caving disasters and search and rescue operations, was standard practice.
Superintendent Knowles took the stand in place of Assistant Police Commissioner Grant Nicholls, who spoke for more than two days.