A team of federal investigators has released new footage with evidence of potential structural and design missteps in the Champlain Towers South building that pancaked in June, killing 98 people in Florida.

The National Institute of Standards and Technology said Wednesday that the footage showed heavily packed steel reinforcement in beams, walls, and columns, and extensive visible corrosion where one column joined the building’s foundation.

Experts have said that the overcrowded reinforcements could have made it difficult to for concrete to bond with the steel creating potential weaknesses in those elements.

The team said it will be conducting an in-depth investigation of the disaster, from the building’s design, construction, and materials, to the moment of its collapse.