Beloved mother killed after lightning bolt strikes tree during 'freak' incident in NSW

A beloved business owner and mother has tragically died after a tree exploded following a lightning strike in NSW yesterday.

Rosanna Hashem was with her friend outside when a lightning bolt struck a tree about 5.30pm in Cawdor, south-west of Sydney.

She died at the scene, while her friend was rushed to the hospital.

READ MORE: Queensland rainfall records smashed as another state prepares for possible cyclone

Jemma Powell, who worked for Hashem for the past seven months, described the incident as "really tragic".

"I was blessed to have known her for a short time," she said.

"She was a beautiful mother of four boys, a loving wife, sole owner of her own business. She had been working hard over the past five years serving the community.

"She was very passionate about animal welfare and just a fabulous person taken way too soon."

Powell told reporters today that Hashem had been sitting on the veranda of her property when she was struck by flying debris.

READ MORE: Greens concede inner-Melbourne seat of Prahran in byelection

"This is the first time that any of us are seeing the scene in daylight so her partner's asked me to share that he thanks everyone for their support," she said.

"He would be standing here now if he wasn't struggling with seeing the scene and his house the way it is."

Hashem owned The Groomery Sydney, which she ran from her property.

"It is with profound sadness that we share the heartbreaking news of Rosanna's passing following an unexpected accident," the business said in a Facebook post.

The business will remain closed until further notice.

READ MORE: Victorian farm placed into quarantine after bird flu confirmed

NSW Ambulance spokesman David Kynaston last night said the second woman, also aged in her 40s, was taken to Liverpool Hospital where she remains in a serious but stable condition.

"Both (women) had been seated about six metres from a large tree and this had been struck by a lightning bolt, which literally caused the tree to explode, sending debris all over the place," Kynaston said.

"This was a freak... traumatic and tragic incident for the family involved but also very confronting for emergency services."

Kynaston said the incident was witnessed by young children.

READ MORE: Man suffers life-threatening injuries after falling from car while riding bonnet

The tragedy comes after parts of the state were hit with a severe weather warning for a "very dangerous thunderstorm" bringing intense rainfall, large hailstones and damaging winds.

Following the Bureau of Meteorology's weather warning, the SES asked residents in High Range, Robertson, Colo Vale, Hill Top and Bowral to "stay indoors" as the storm passes.

The system impacted Nattai National Park, Yerranderie and the Nattai Tablelands before moving northeast towards Oakdale, the western parts of the Wollondilly Shire and the area west of Picton.

DOWNLOAD THE 9NEWS APP: Stay across all the latest in breaking news, sport, politics and the weather via our news app and get notifications sent straight to your smartphone. Available on the Apple App Store and Google Play.