America an engineer who has warned great damage to the structure of the 12-storey apartment Champlain Towers South three years before being collapsed on June 24.

Surfside officials at the end of June 25 announced an engineer's 2018 report, Frank Morabito consultant, which stated that the design of the Champlain Towers South Apartment Building had a big mistake.

The failure to replace the waterproofing layer in the near future will cause the level of damage of concrete to increase according to multiplier, Morabito warns.

Rescue teams seek survivors of 12-storey apartments in Surfside, near Miami Beach, Florida state on June 25.

He said the replacement of waterproofing will cause great inconvenience for residents and very expensive.

Although not mentioning the risk of collapsing in the report in 2018, Morabito notes to complete the repair to maintain the structural integrity of 136 apartments.

In addition to Morabito's report, a study of 2020 indicated Champlain Towers South was subsided with a speed of 2 mm per year since the 1990s.

12-storey apartment Champlain Towers South in Surfside town, near Miami Beach, Florida, suddenly collapsed on June 24, causing at least 4 people to die and 159 people missing.

Search groups work alternately with the support of professional dogs, camcorders and audio navigation devices.