A Sydney couple, their two autistic children and their dog have been found dead in their home in what police say is a "tragic" event.
The alarm was raised on Monday after Colombian-born Maria Claudia Lutz, 43, didn't show up for her volunteering shift at special needs school St Lucy's, and her children weren't in class.
Police found Ms Lutz's body at around 11:20am that morning inside the family's home, alongside the body of her husband Fernando Manrique, 44, their children Elisa, 11, and Martin, 10, and the family dog.
Northern Beaches police Superintendent Dave Darcy said it was a tragic and horrific event.
"It's extremely confronting... we consistently have these concerns for welfare cases, and unfortunately in some cases this is what the police are confronted with."
Supt Darcy said it's "far too early" to speculate on the circumstances, including whether it could have been a case of murder-suicide.
"There is no one telling us at the moment what has happened. There is no one who has witnessed it."
The whole community has been shaken by the sudden deaths.
"I used to walk up to the oval and they'd say hello," neighbour Sonja Perry told the Daily Telegraph.
"They were just a normal family, the kids would play in the front yard."
Ms Perry said sometimes Ms Lutz had found it difficult to cope with raising Elisa and Martin. It's understood both of the children had high complex special needs.
"[She] used to tell me how hard it was on her and her husband having two kids who were deaf and dumb," Ms Perry said.
"They were... such a lovely, friendly couple. I'm shocked to see police cars outside their house. They never caused anyone problems."