FIRST ON 7: A runaway semi-trailer has rolled down a driveway, across a road, and slammed into the side of a house in Sydney's north-west.
Nobody was injured, but the crash triggered an asbestos scare, and fears the house could collapse.
The driver was hitching trailers onto the B-double at the Original Pretzel Company factory, when the truck started moving.
He jumped out of the way, only to see it demolish the loungeroom of a fibro house on Sefton Road at Thornleigh.
Resident, Brooke Lane, was supposed to be home at the time.
"She only works part time so there's quite a few days of the week she's home and she would have been sitting in the lounge room right when the truck went through," Brooke's boyfriend Dylan Jones said.
Council engineers were called to work out how to remove the semi, and there were concerns that the building contains asbestos, and is structurally unsound.
The truck has now been stuck for about several hours, and 7News has been told it's a delicate operation to remove it.
The whole accident has created a delicate issue amongst the Thornleigh household.
As police inspected the damage, they stumbled upon a marijuana plant, leaving officers with more than just a runaway truck to investigate.
"I told [my flatmate] to get rid of it, so sucked in if you ask me, nothing to do with me," tenant Darren Hall said.