CANBERRA, May 24 (Xinhua) -- A meteor that crashed into the ocean off the coast of South Australia (SA) on Tuesday night would have caused fatalities if it hit the state, according to astronomers.

Footage emerged on Wednesday of the fireball streaking across the SA sky, with authorities receiving multiple reports of sightings.

According to The Australian on Friday, it crashed into the ocean approximately 400 km off the coast near the border of SA and Victoria.

Astronomer David Finlay said it was the biggest meteor event he has seen in the four years he has been running an Australian meteor report website, saying it would have been lethal even after breaking up in the atmosphere if its fragments landed in a populated area.

"We're estimating that around 3 to 4 tonnes would have survived atmospheric entry," he said.

"If this was over Adelaide, you would be looking at fatalities ... I'm not trying to be alarmist here, that's just the reality of it.

"If it was over a populated area we would essentially be looking for holes in roofs and cars."

It was Finlay estimated that before breaking up it weighed between 20 and 40 tonnes and was travelling at 40,000 km per hour (kmph). He said it would have had an explosive yield of 1.6 kilotons.

"When you think of the Hiroshima nuclear bomb, that was 15 kilotons, so the South Australian fireball was 10 percent the explosive yield of Hiroshima," he told the Australian Broadcasting Corporation (ABC).

"Imagine a (small car) that's just all rock entering the atmosphere, that's essentially what's happened here.

"This is the biggest event we've seen."