The first flowers were laid at Yerrabi Pond when search efforts ended on Sunday after the body of missing boy Pranav Vivekanandan was found.
It follows the discovery of an adult woman and male child in the water on Saturday, and police issued a missing person notice for Pranav.
In a statement on Sunday morning, police said the eight-year-old boy was "located deceased in Yerrabi Pond".
"The investigations into his death, and those of his mother and brother who were also discovered deceased in Yerrabi Pond yesterday, are continuing," ACT Policing said.
The usually vibrant, loud and happy Yerrabi Pond Distract Park had a more solemn atmosphere as members of the public slowly walked past the area where police investigations took place.
After Pranav's body was taken from the water, police tape, tarps and equipment were packed up and gone by midday.
Only piled up weeds and leaves were left to mark the police's one-and-a-half day search for the three bodies.
A family barbecue for a child's birthday was taking place, however members of the party were quietly chatting as children enjoyed the playground.
Many members of the public sat under a tree, looking out quietly to the pond and one family came to the bank with their four-year-old daughter, muttering their disbelief over the recent tragedy in their community.
Peter Toscan's home looks out to Yerrabi Ponds and he laid flowers where the tragedy occurred, hoping it would be the first of many tributes to come.
"What a tragic event ... I just felt somewhat depressed about the whole thing ... I had to do something," he said.
"I think it's just a sad occasion where mum and her two children have passed away ... it's just such a sad event."
Divers searched the water from Saturday morning until late and recommenced on Sunday when Pranav's body was pulled from the water around 10.45am.
Officers found the bodies of Pranav's mother and brother after a member of the public saw them in the water around 8am on Saturday, while investigators later recovered a white Subaru from the banks of the pond in Gungahlin.
The car had a baby seat in the back, and was said by locals to be at the edge of the water since about 4am.
Rod Wheatley said on Facebook the car was blocking access for a truck at 4.12am. "I opened the gate, noticed it was not locked with a child seat in back. I actually opened the door to see if keys (no keys) were in it, to move for access."
At this stage of assessment, police do not believe another party was involved with the incident.
A report is being prepared for the Coroner and it is expected ACT police will provide an update around the middle of next week.
At a press conference on Saturday, detective superintendent Hall O'Meagher said about 30 police officers were involved, including divers and a drone operator. Emergency service workers were also at the scene.
"This is obviously a tragic situation," Mr O'Meagher said.
"Our thoughts go out to [the family] and also to the responding police who have had to deal with this tragic circumstance."
Counselling was being made available for officers and SES personnel involved in the search effort.
While there was no appeal for information about any other specific person, ACT Policing have called for anyone with any information which may be useful to contact Crime Stoppers on 1800 333 000, or on the Crime Stoppers ACT website.
-
Support is available for those who may be distressed. Phone Lifeline 13 11 14; Mensline 1300 789 978; Kids Helpline 1800 551 800; beyondblue 1300 224 636; 1800-RESPECT 1800 737 732.
