WELLINGTON, New Zealand — A six-story building that collapsed and killed 115 people in last year's New Zealand earthquake was made of weak columns and concrete and did not meet standards when it built, the government said Thursday.

The building's designer contested the findings and said the report itself was "technically inadequate." The report could open the door to legal claims by victims' families and police are considering whether to open a criminal investigation.

The Canterbury Television (CTV) building fell into a smouldering heap when the magnitude-6.1 earthquake shook Christchurch last Feb. 22, and its collapse accounted for nearly two-thirds of the quake's 184 victims.

New Zealand's Department of Building and Housing concluded that the CTV building didn't meet minimum requirements when it was built in 1986 -- and would fall far short of the latest standards.

The report is the first to find construction flaws in a building that collapsed during the earthquake. Investigations into other buildings that at least partially failed found all were built to code requirements but failed due to the intensity of the quake.

Brian Kennedy, whose wife Faye died in the CTV collapse, said said the report helps give him at least some sense of closure.

"It gives me a feeling that I understand exactly what happened, how quick it happened, and that thank god it didn't happen to other buildings," he told The Associated Press.

As to legal matters, he said family members would first likely want to hear from the designers, builders and inspectors at an ongoing inquiry into the quake and then "take it from there."

New Zealand police say they are considering whether to launch a criminal investigation based on the report's findings. Assistant police commissioner Malcolm Burgess told reporters there is a high threshold to establish criminal liability in such cases.

In its report, the building department concluded that load-bearing concrete columns were reinforced with insufficient steel, making them brittle, and that the columns' asymmetrical layout made the building twist during the quake, placing extra strain on those columns. Tests after the collapse also found the concrete in load-bearing columns was "significantly weaker than expected" the report said.

"It is evident that the building collapsed straight down almost within its own footprint," the department found. "Eyewitnesses spoken to as part of the investigation saw the building sway and twist violently. One ... described the whole exterior exploding and seeing the cladding failing and falling, and columns breaking."

The report didn't specify who was to blame for the shortcomings -- the architects who designed the structure, the construction company who built it, or the officials who inspected it -- although there is probably plenty of blame to go around. The ongoing inquiry into the earthquake may find some more answers to those questions.

Alan Reay Consultants, which carried out the building's initial structural design, disagreed with the report.

"Personally I feel incredibly torn," Alan Reay, the company's director, said in a statement, issued immediately after the report came out. "I have huge empathy for the families waiting for answers, but these reports are technically inadequate ... Some of the assumptions made in the reports are highly questionable."

The report notes that drawings for the building fail to show a required gap between the columns and the beam panels that extended outward from those columns. The gap, which allows movement during an earthquake, was required to be 19 millimeters (3/4 inch) but in the drawings was only about half that.

The report also found that the drawings showed no reinforcing steel for the connections between some walls and floors. The omission was discovered in a 1991 review of the building for a potential buyer, the report said, which led to the installation of some steel connectors then. But the report concluded the additions were insufficient to make the building strong enough.