The mother of a seven-year-old boy killed in a tree-felling incident in Tasmania has told a manslaughter trial how she tried to protect three children as they sat in a ute.
Sierra Lynd was on a trip to cut and collect wood with her son Akria, two younger children and former partner Joshua George Hector Clark at Mt Lloyd in the state's south in August, 2015.
Clark, who has pleaded not guilty to manslaughter, is accused of failing to take reasonable precautions when using a chainsaw to fell a tree.
Ms Lynd said she was sitting in the passenger seat of the ute on a remote track with the children in the back seat when she saw a tree falling towards them.
"I heard (Clark) say get the f*** out of the car," she told the Supreme Court of Tasmania in Hobart on Monday.
The court was told Akira was struck on the head by the tree after he got out of the car, suffering skull fractures.
He was flown by helicopter to hospital and died the next day after his life support was turned off.
Ms Lynd said she flung a younger boy from a car seat to the back of the ute as the tree approached, while a girl managed to get out of the car but suffered a broken collar bone.
"I scooped (Akira) up and ran to the back of the (ute) tray," she said, describing the moments after he'd been struck.
She said Clark had cut down a "green tree" but would usually cut down dead trees.
Crown prosecutor Heather Denton said the jury would hear from a forestry expert and former WorkSafe Tasmania inspector who would say the ute was parked in the "drop zone".
Ms Denton said Clark failed to cut a wedge in the tree, had no control over which way it fell and should not have cut a tree that was supporting another.
Ms Denton said the area was a timber production zone and Clark didn't have permission to cut down trees or collect firewood.
Ms Lynd said she would go wood cutting regularly with Clark and agreed he was always very cautious. She said she stayed in the car with her kids on the day in question because it was cold.
"They were eating their chips. We were talking about what we were going to do when we got home," she said.
The court was told Ms Lynd and Clark both called emergency services, with Ms Lynd saying they took "quite some time" to arrive.
"As I was just about to get in the helicopter (Clark) told me to make sure I told the cops it was a f***ing accident," she said.
Clark told police at the scene he saw a large tree resting on another tree and cut it down because he believed it was in a dangerous position near the road, the court was told.
The tree, which compressed the ute's roof to the height of its rear seats, was 32 metres long and the cut section 22 metres long, Ms Denton said.
The trial is expected to run for four days.
