PHOENIX >> Iris Ross had a cordial telephone conversation with her estranged husband on Christmas Day before she left to pick up their two children at his apartment in Phoenix, a friend said today.

It was the last time Pam Alexander saw her friend alive.

Ross and the children were later gunned down by her estranged spouse, Anthony Milan Ross, police say.

Alexander, whose daughter was a roommate of Iris Ross, said all three of them had been preparing the house for more than 20 guests for a Christmas dinner that the children were supposed to attend.

“There was nothing that would indicate at that time any sort of conflict that had arisen,” Alexander said. “He called her later and she left the house a little before 3 p.m. Quickly after that, it all just went to hell.”

Anthony Ross was being held today without bail on three counts of first-degree murder and other charges. It was not clear if he had an attorney.

The shooting came just hours after Anthony Ross posted a video on Facebook in which he and his 11-year-old son, Nigel, are seen laughing and singing “Santa Claus Is Coming to Town.”

Both parents agreed Nigel and their 10-month-old daughter, Anora, should stay a few hours longer with their father because the infant was fighting a cold, Alexander said.

Alexander met Iris Ross and her kids for the first time after arriving to visit her daughter last week. She said it was beyond surreal to go from playing with the children Christmas Eve to helping the family with a GoFundMe page to raise money for three funerals.

“You just can’t wrap your head around stuff like this,” she said.

Alexander and her daughter immediately drove to Ross’ apartment complex after they heard about the shooting. Police were already there following reports of gunfire.

Police found Iris Ross’ body on a front patio of the building. Witnesses said Anthony Ross was going through her pockets when they approached him. Court records say he pointed a gun in their direction then barricaded himself inside his home.

After several hours, police used a robot to enter the unit and determined the infant was dead. Police say Ross began firing at officers before a SWAT team entered and exchanged gunfire.

Ross was taken into custody without injury. The boy was found dead in another room.

Police did not give a motive for the shooting, which is being investigated as a domestic violence incident.

An advocate of vegan eating, Anthony Ross wrote cookbooks and often spoke about how he lost half his body weight with his healthier lifestyle. He spoke on the subject on TV, often crediting his weight loss with strengthening his relationship with his son.

“He looks at me like his hero now,” Ross told the national lifestyle show “The List” in an August episode.