On Monday 24 December 2018, loud cracking noises were heard by Opal Tower residents and many experienced increasing difficulty opening doors as door frames warped. Several cracks were observed in concrete panels on level 10, sparking fears that the tower might collapse and prompting several residents to evacuate.

After receiving several Triple Zero calls at about 3.00pm, Fire and Rescue NSW (FRNSW), NSW Police (NSWP) and Ambulance NSW attended the scene, with NSWP responsible overall for incident management. Evacuation of the tower was completed, and a 300-metre exclusion zone was established. 1,700 people from Opal Tower and other nearby buildings were displaced. A temporary evacuation centre was established nearby at the Sydney Showground.

NSW Public Works engineers, FRNSW urban search and rescue specialists and a representative of the building designers inspected the tower, concluding that it was not in danger of collapse, allowing most residents to re-occupy the building the following day. However, residents in 51 of the units were only able to return briefly to retrieve pets, medications and essential personal items. On 27 December, all residents were evacuated again while a more thorough engineering analysis was conducted.

The NSW Government initiated an independent investigation into the cause of damage to the tower, how the damage could be rectified and sought recommendations that would assist in avoiding problems with future high-rise construction in NSW. The final report was delivered to the NSW Minister for Planning and Housing on 19 February 2019.