Photos show extensive damage underneath the pool of the Florida condo 2 days before the building collapsed

• A pool contractor visited Champlain Towers South pool-equipment room last week.
• His photos, published by the Miami Herald, showed cracked concrete and damaged reinforcement bars.
• Two days after the contractor's visit, the building collapsed. 11 people are confirmed dead.

Photos taken in the pool-equipment room of Champlain Towers South in Surfside, Florida, two days before it collapsed showed extensive damage.

The photos were taken by a pool contractor who visited the condo last week, and shared with the Miami Herald's Sarah Blaskey and Aaron Leibowitz.

The photos showed cracked concrete on the walls and severely damaged rebar - reinforcement bars - under the pool, the Herald reported.

The contractor, who asked not to be named, also saw a puddle of standing water in the parking garage, but did not photograph it, the Herald reported.

The photos came as experts told The New York Times that video of the collapse suggested that the disaster was caused by something at the bottom of the building.

It remains unclear what caused the building's collapse or whether the damage under the pool had any effect on the collapse.

The condo collapsed early last Thursday morning. Eleven people have been confirmed dead, and 150 people are still missing.