A South Australian regional community is grieving the loss of Helena Wright and her daughter after a shocking tragedy.

The 36-year-old’s body was found in the water off Port MacDonnell on Monday, alongside her young daughter. Police believe they might have fallen from a cliff.

WATCH ABOVE: Mother identified after sad family tragedy in SA regional town

Know the news with the 7NEWS app: Download today

The heartbreak deepened when it became clear her three-month-old baby boy was missing and so far has not been located.

The alarm was first raised when a member of the public spotted a car near the cliff’s edge with its engine still running. An officer made the grim discovery a short time later.

Helena Wright, 36, a much‑loved mother from the tight‑knit community of Compton Credit: Facebook/7NEWS

Wild conditions continued to hammer the coastline on Tuesday, forcing emergency services to cut short their desperate search for the missing infant.

Police boats launched at first light but were pushed back by rough seas, shifting the search to land as volunteers combed the cliffs and shoreline.

Superintendent Trent Cox said conditions had become “extremely challenging”.

“Sadly we have not been able to locate the boy, but we will resume the search tomorrow morning,” he said.

“It became too dangerous to continue.”

Search efforts have been hampered by bad weather Credit: 7NEWS

As the search entered its second day — nearly 40 hours since the baby went missing — Cox said he did not believe the infant would be found alive.

“We will continue to take the advice of search and rescue experts,” he said. “There are a number of factors to consider, one of them being the weather conditions and the age of the missing child.

“The information we have from survivability experts is that it is very, very unlikely the missing baby has survived to this point.”

Police Commissioner Grant Stevens said the tragedy had deeply affected those involved.

“As you can imagine, searching for a small child and recovering a woman and a child from the water will take its toll on people who are involved in that search exercise,” he said.

Police believe Helena had fallen off a cliff Credit: 7NEWS

South Australian Premier Peter Malinauskas said the deaths “shocked you to the core”.

“Wherever we see the loss of anybody, it’s a tragedy. Where it involves children, that breaks your heart,” he said.

Local mayor Kylie Boston, meanwhile, said the community was shocked.

“I think everybody is just kind of stunned because you hope these things don’t ever happen,” she said.

Boston said locals were already rallying around one another.

“We all pull together, we get there,” she said. “Everyone will go and have a cuppa together at footy, or have a few beers at footy, netball, hockey — whatever they do over the weekend — and we talk about it. And I think that’s how we bounce back from these sorts of things.”

Police have spoken with Wright’s husband. At this stage, investigators say there is no information to suggest anyone else was involved. A report will be prepared for the coroner.

Police are seeking information from anyone who saw her car — a white 2015 Isuzu MUX, SA registration S592BJR — or has dashcam footage.

If you need help in a crisis, call Lifeline on 131114. For further information about depression contact beyondblue on 1300224636 or talk to your GP, local health professional or someone you trust.