The two young children who fell from the top of a Boston parking garage on Christmas were likely killed by their mother before she jumped to her own death, officials said Thursday.

"The evidence collected thus far suggests that these deaths … were very likely a double-murder suicide," Suffolk County District Attorney Rachael Rollins told reporters.

The mother, Erin Pascal, 40, and her two children, Allison, 4, and Andrew, about 1½, were found Wednesday at the bottom of Renaissance Park Garage near Northeastern University in the city's Roxbury neighborhood, police and prosecutors said.

City, campus and mass-transit police responded to the scene around 1:26 p.m. and rushed all three to hospitals where they were pronounced dead, officials said.

"This entire family, in a matter of minutes, aside from the father who survives them, is gone," Rollins said.

The woman's SUV, which contained two children's safety seats, was found on the garage roof.

Rollins described to WBUR radio on Thursday the chaotic scene where police found the three bodies.

"It was awful," she said. "There were children's shoes and an adult shoe. ... There were belongings from the children and the mother strewn upon the street."

"There was the impact of the fall was visible from the street," Rollins added.

Wednesday's suicide was the third at this parking garage this year, following deaths on May 20 and Dec. 9, the prosecutor said.

In that May 20 incident, Boston College student Alexander Urtula, 22, died less than two hours before his graduation ceremony, prosecutors said.

Urtula's girlfriend Inyoung You, 21, is facing a charge of involuntary manslaughter from Rollins' office. Prosecutors allege that during the 18 months that Urtula and You dated, she exerted control over him, tracking his movement via his cellphone and sending thousands of texts in the run-up to his death.

After Wednesday's incident, Northeastern "blocked both pedestrian and vehicular access to the top two floors of the Renaissance Park garage," according to a university statement.

The school didn't immediately say if Pascal had any connection to the campus.

The Christmas Day deaths caught the attention of Mayor Marty Walsh, who tweeted: "This is a horrible tragedy for this family on this Christmas Day. My prayers and deepest sympathies are with them."

If you or someone you know is in crisis, call the National Suicide Prevention Lifeline at 800-273-8255, text HOME to 741741 or visit SpeakingOfSuicide.com/resources for additional resources.