The sole engineer who inspected Christchurch's CTV building after the September 2010 quake rocked the city has told a royal commission he believed the building was structurally sound, and has repeatedly questioned himself on whether he made the right conclusion.
David Coatsworth carried out a visual inspection of the building on September 29, 2010, and on October 8 he filed a report saying the building had not sustained significant structural damage.
He recommended repairs to fix small cracks in concrete beams and walls.
The building later collapsed in the February 2011 quake, killing 115 people.
Mr Coatsworth told the commission in Christchurch on Wednesday he had "relived" the four-hour inspection over and over, and reviewed his photos and report since.
"I ask myself if there was anything I should have done differently."
Mr Coatsworth said he had been unable to get the building's architectural drawings from the building's manager or Christchurch City Council to assist his report, The Press reports.
He finished his evidence by giving his condolences to the families of those who died in the building.