Heritage home destroyed in suspicious blaze after explosion shook nearby homes

Police are investigating a suspicious blaze which has destroyed a heritage-listed South Australian home.

The 164-year-old Willunga property burst into flames after a dramatic explosion shocked neighbours awake just after 5am.  

"It shook my whole room for like two seconds, it made me actually jump out of bed," one neighbour said.

READ MORE: When we will know who won the presidential election?

The blast was so powerful, it blew off the roof and sent glass soaring across Aldinga Road.

Nearby residents were forced to evacuate as firefighters battled the blaze.

"It must've been a pretty large explosion and set the house on fire," the Country Fire Service's Darren Saunders said.

READ MORE: America about to make history – no matter who wins

Investigators suspect the fire was deliberately lit.

"It hasn't been occupied for a period of time, hence why it is being treated as suspicious at this stage," Saunders said.

Built back in 1860, the old cottage is a treasured piece of the community's history. 

"It's got some beautiful heritage features, it's on our local heritage list and Willunga we care a lot about our heritage so this is a blow," National Trust of South Australia chair Paddy O'Toole said.

Neighbours who feared for their safety took matters into their own hands and hosed down the blaze from their fence line to try to prevent their properties from going up too.

No one was injured or inside the home when it burst into flames.

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.