An Amber Alert for Nathan is still in effect and investigators are looking to speak with anyone who attended a weekend estate sale at the home of his grandparents.
June 27-29: Alvin and Kathy Liknes hold an estate sale at their Parkhill home in southwest Calgary from 2 p.m. to 7 p.m. MT Friday and 8:30 a.m. to 4 p.m. MT Saturday and Sunday. The couple had recently bought a house in Edmonton and planned to clear out some things before moving. The O'Brien family comes over to help out with the sale throughout the weekend.
June 29, around noon: A neighbour sees Alvin Liknes at a nearby park playing with Nathan.
June 29, 10 p.m.: The estate sale is over and the O'Brien family heads home after a day of helping out. Nathan's mother, Jennifer O'Brien, leaves him with his grandparents for a sleepover.
June 30, 10 a.m.: Jennifer O'Brien returns to pick up Nathan but finds he and his grandparents are not in the house.
June 30, 5:15 p.m.: Police issue an Amber Alert for Nathan.
June 30, evening: Police announce evidence in the house has led them to believe the disappearance of Nathan and his grandparents may be suspicious.
July 1, 11 a.m.: Investigators say they have no "significant leads" about the whereabouts of the missing boy and his grandparents.
July 2, 3 p.m.: Nathan's parents, Rod and Jennifer O'Brien, speak to media. They call Nathan a superhero, ask him to stay strong as the police search continues and make a tearful plea for his return. Police say they have decided not to offer a cash reward at this time.
July 3, 10 a.m.-10 p.m.: Investigators are at the Parkhill Community Centre to speak with anyone who attended the weekend estate sale. People are being asked to bring photos of what they bought to help investigators catalogue what was purchased and what remains in the house.
July 4, 11 a.m.: Calgary police ask for the public's help in identifying a vehicle seen in the area the night Nathan and his grandparents disappeared. They say they want to speak with the driver, who they believe might have more information about their disappearances. For a description of the truck, click here.
July 4, 2 p.m.: Calgary police are expected to hold a news conference about the case.