In their latest update on the Surfside, Florida, Champlain Towers South condo collapse, investigators have released new videos that confirm the sequence of events but fail to explain what triggered the condo’s collapse.

The newly-released videos were shown at a March 7 meeting of the National Institute of Standards and Technology advisory committee, which has been trying to understand why the condo collapsed, killing 98 people.

After more than two and a half years of evidence gathering and analysis, and $30 million later, investigators say they are zeroing in on what they call the “initiating event.”

Since the morning of the collapse, it has been understood that a portion of the swimming pool deck collapsed before the tower, but survivors of the catastrophe have said they heard knocking noises like a hammer in the tower minutes before the building fell, which raises questions about whether there was a failure in either the tower or the garage that resulted in the pool deck collapse.

Investigators said the videos make it fairly clear that the first collapse was in the pool deck, but that doesn’t mean the initiating event wasn’t somewhere else.

Investigators also reported that while construction drawings were made to code, the construction itself was not. Portions of both the tower section of the condo as well as the pool deck did not meet the building code requirements when it was built in 1981.

“We've discovered several places where the building did not meet the requirements of the drawings, the building code, or common practice,” said Jim Harris, an engineer on the team.

Investigators have noted that the problems found in the construction of the pool deck continue to appear the most egregious.