The Planning Department has received a flood of concerned calls about retaining walls around the Island in the wake of Wednesday's tragedy at the Bermuda College, said planning director Rudolph Hollis.

The Education Centre's teachers' aide Andrea Trott Bicari was killed on Wednesday morning as she sat in her car when a retaining wall adjacent to a parking lot at the College collapsed on top of her.

"We've received quite a few calls (from people concerned about retaining walls)," said Mr. Hollis.

It was difficult to pin down exactly how many calls the department had received, he said, as different people in different departments were receiving the calls, from the building inspectors all the way through to front desk.

"Some of them are genuine, some are just general enquiries, and some are even anonymous," said Mr. Hollis.

Regarding what the Planning Department meant to do about the problem, Mr. Hollis was unsure about the course of action to be taken. "We are discussing with our Ministry now in terms of how we should approach that situation," he said, although he could not say when he would know what the solution will be.

Former planning director and current United Bermuda Party MP Erwin Adderley said he was very concerned about some of the terrain that walls and roads had been built on and urged the public to be vigilant.

He said: "Along the South Shore between Paget and Whitehill, Somerset, it's renowned for very sandy soil. It's almost all sand. Over the years walls and roads in that location have collapsed and crumbled. It's not a new phenomenon.

"I would have thought the director of planning would have sent out a memo saying you have to be careful with walls in that location."

He said mid-way in his spell heading planning new standards of wall building had been instigated after concerns about building on sandy soil.

However, he said there was very little Government could do with walls already up.

He said the Planning Department could only condemn a structure when defects became obvious and have it pulled down.

"It's like looking at a crystal ball - what walls built are in a state of possible collapse? It's very difficult to determine. You can't dig half of it up. It's something you have to live with.

"I think in the last 20 years we have been doing our due diligence in terms of construction walls."

He said collapses were often brought on by hard rain which saturates the sand and adds to the pressure.

He said the traditional way of building retaining walls in Bermuda with concrete blocks with draining holes supported by reinforcing rods and foundations worked at 90 percent of locations but was inappropriate for South Shore.

"It doesn't work if you are building a high wall or in sandy conditions."

In these other conditions structural engineers had to design a wall in accordance with the soil conditions, said Mr. Adderley.