Eleven-month-old Scott Steele didn't get the chance to play with his sister Abbey, on the right. He was killed when the car he was travelling in was hit by a truck at a junction in Dee Why, the same corner where a truck overturned on Tuesday morning.

Scott's mother Sue Steele was burnt on 20 per cent of her body in the accident in April 2000. Four-year-old Martin, pictured on the right, was snatched to safety.

Mrs Steele spoke of the horror she felt when she saw the video of the truck overturning in the same spot on Tuesday, crashing into nine vehicles.

Two off-duty police officers injured in that incident remain in hospital. The female officer is in an induced coma and her condition is serious but stable.

"You go through so much but you can't let it affect you to the degree that it did again on Tuesday - that was a horrible day," Mrs Steele said. "I was really upset and so was my husband Stephen."

Mrs Steele said no matter what roads heavy vehicles travelled on in the northern beaches area there would be a danger to the public.

"It's tricky on the northern beaches because there are only a few ways to come in and out," she said. "I do believe that trucks should be in a separate lane."

In 2003, truck driver Mosleh Mekhael was sentenced to seven years' jail with a non-parole period of four years for the manslaughter of Scott.

The court found that Mekhael, then aged 30, drove downhill with defective brakes at triple the heavy vehicle speed limit before ploughing into Mrs  Steele's car at the intersection of Warringah and Pittwater Roads.

The judge said the Roads and Traffic Authority had acted "reprehensibly" when it allowed Mekhael's tip truck to be registered without an inspection because of a computer error.

Mrs Steele said the scars after four skin grafts meant she could not wear a bikini but the greater trauma was the psychological suffering she endured.

After the incident, the family returned home to Wales for a period. Mrs Steele suffered panic attacks and was unable to face driving. Her son Martin is now a P-plate driver and lives near the scene of the crash.

When Abbey was 11 she saw the picture of the three children blended into a single image.

"Of course, they had never been together," Mrs Steele said. "She saw it and it broke her heart.

"She misses the fact that she had a brother she's never met. It changed the whole dynamics of the family, because now we have got two kids that are so far apart in age they don't have much in common.  Martin's 19 and Abbey is 13. Scott would have been 15."

Roads and Maritime Services said the vehicle involved in Tuesday's crash was last inspected in May and found to have only minor defects.