ONTARIO -- A 3-year-old boy died Monday night after his uncle accidentally backed over him with a sport-utility vehicle, police said Tuesday.

Jesse Antonio Rivas was running to catch up with his uncle, Tanislado Sanchez, when he was struck by Sanchez's SUV at 7 p.m., Officer David McBride said.

"He was going to try to park on the other side [of the street]," said the boy's aunt, Maria Diaz. "He just said he felt something, but he never thought it was a kid."

Sanchez got out and found that Antonio had been run over. The family called the boy Antonio because his father's first name also was Jesse.

"He grabbed him and carried him, and started screaming," Diaz said.

Cpl. James Renstrom was the first officer dispatched to the 2000 block of South Lemon Avenue. He found the child lying in the street with massive head injuries and started CPR. The Ontario Fire Department arrived and the boy was taken by ambulance to Arrowhead Regional Medical Center in Colton.

He was pronounced dead there at 7:45 p.m., San Bernardino County coroner's spokesman Randy Emon said.

Officials called the family to relay the news.

"Everybody was ... hitting the cars, everything," Diaz said. "We couldn't even believe it."

Diaz said that Sanchez has been inconsolable since the accident.

Antonio was visiting relatives Monday afternoon. When Sanchez took the Toyota 4-Runner to get groceries, Antonio said he wanted to go along, Diaz said.

"Tani said, 'No, I can't take you,' " Diaz said.

When Sanchez returned with the groceries, he first parked in the driveway before deciding to move the vehicle across the street to allow other cars to get out. Antonio spotted the 4-Runner and probably believed that Sanchez was leaving, McBride said.

"I think he felt, 'My uncle's leaving, I want to go catch up with my uncle,' " McBride said. "He backed out of the driveway, and unfortunately, he just couldn't see him."

Emon said an autopsy was performed Tuesday. The cause of death was listed as "multiple blunt force injuries."

Investigators plan to submit a report to the district attorney's office for a routine review, but they do not expect charges to be filed.

"I don't see anything conceivable," McBride said. "I would be very surprised if they file any charges. Bottom line, it was an accident."

The boy's mother, Silvia Diaz, and his father, Jesse Rivas, also have a 1-year-old daughter, Jasmine. The family had just returned from a weekend in Juarez, Mexico, where they were celebrating a quinceanera.

Maria Diaz said her nephew often played with her 3-year-old son, Osvaldo, and each boy would blame the other when they both came home covered in dirt.

"He was tremendous," she said. "It's so sad."

A memorial of balloons and candles was placed at the spot where Antonio was struck, and his name was carved into a nearby tree, under the inscription "In Love & Memory." If you want other stories on this topic, search the Archives at latimes.com/archives. For information about reprinting this article, go to www.lats.com/rights.