The Christmas Day deaths of a mother and her two young children found outside a Boston parking garage appears to be a double murder-suicide — with the mom forcing her kids off building’s roof before she jumped, authorities said Thursday.

Erin Pascal, 40, likely caused her 4-year-old daughter Allison and 16-month-old son Andrew to plunge from the roof of the Renaissance Park Garage before jumping herself, around 1:30 p.m. Wednesday, Suffolk County District Attorney Rachael Rollins told reporters.

“The evidence collected thus far suggests that these deaths… were very likely a double murder-suicide,” Rollins said.

No suicide note has been found.

Sources told WBZ-TV that Pascal took off with the kids from their West Roxbury home following a dispute with their father, whom she lived with.

The dad called 911 to say that Pascal appeared suicidal, according to the outlet.

Pascal and her children were found unconscious on the pavement at the base of the nine-level garage, and they were pronounced dead at a hospital.

The scene was “awful,” Rollins said.

“There were children’s shoes and an adult shoe. Just belongings from the children and the mother strewn upon the street. The impact of the fall was visible from the street,” the prosecutor said.

Investigators are still searching Pascal’s black SUV — which was left parked on the rooftop with three of its doors open — as well as her phone and any surveillance footage, Rollins said.

Police previously said two car seats were found in the vehicle, one forward-facing and one backward-facing.

“For a parent to come to a place where they harm their children in this way indicates that their mental health struggles were severe and in need of immediate support,” Rollins said, as she urged anyone in need to seek help.

“This Christmas Day tragedy demonstrates the urgency of addressing mental health,” she said.

The investigation is ongoing.

With Post wires