The collapsed Miami condo had regular floods in the basement garage which could've seriously damaged it, reports say

• The basement garage of the collapsed Miami-area building regularly flooded, multiple people said.
• Residents, a contractor and maintenance worker noted that standing water was a persistent issue.
• It could have been a factor leading to the collapse of the building, one expert said.

The basement garage of the Miami-area apartment building that partly collapsed would regularly flood, according to multiple sources.

The accounts add to the list of problems with the building which have emerged since its collapse Thursday, which has killed at least 11 people and left some 150 more unaccounted for.

William Espinosa told CBS 4 Miami that he was responsible for maintenance at Champlain Towers South between 1995 and 2000. He said that sea water would seep into the buildings foundations and employees would use pumps to drain it.

"The water would just basically sit there, and then it would just seep downward," Espinosa said. "I'm talking about a foot, sometimes two feet, of water in the bottom of the parking lot, the whole parking lot."

Espinosa said that he alerted building managers to the flooding, who he said did not take action.

"But I go, 'You know that it's endless,' " he said. "And I go: 'This is just not normal. I mean, this is just too much water.' "

A contractor who visited the building last Tuesday, some 36 hours before half of it collapsed, told The Miami Herald the basement-garage area was flooded when he visited, and shared images of the standing water .

"There was standing water all over the parking garage," said the contractor, whom the Herald did not name.. He said there appeared to be signs of structural damage.

John Turis, a resident who was out of town when the apartments collapsed, said that basement flooding was a regular occurrence.

"There was always water in the garage. There was always water leaking - it used to leak on my car all of the time," he told The Washington Post.

The claims echo a 2018 engineer's report which found that water was unable to drain out of the basement properly, which it attributed to a serious design flaw .

The report described "abundant cracking… of columns, beams and walls" in the garage. It did not flag the structure as being at imminent risk of collapse.

Henry Koffman, a professor of civil engineering at the University of Southern California, told The Washington Post that flooding of the garage could have contributed to the collapse.

He cautioned that there is too little information so far to say if the flooding was a decisive factor.

"It's surely not good," he said. "Standing water or any kind of water, you need to get it out right away."

Rescuers on Monday were searching for pockets of air in the heap of rubble where the building stood, hoping to find survivors trapped there.

But hope was fading that anyone could still be alive five days after the collapse.

As well as the 11 people confirmed dead in the collapse, nearly 150 remain missing.

The White House has said a federal investigation into the cause of the collapse is likely.