A witness to the fall that killed a mother and her 2-year-old son Saturday at a Padres game said the woman was jumping on the bench of a picnic table with the boy in her arms when they both went over the railing.

The two were killed at about 3:50 p.m. when they fell 60 feet to the sidewalk below the third-level concourse of Petco Park in San Diego.

Police have not released the names of the pair, but said the woman was 40 years old and from San Diego. She and the child were at the game with the child’s father.

The witness, who did not want to be named but spoke to TV stations including NBC7, said she had noticed the family in the concourse dining area — first because they had a dog with them, and then because of the woman’s risky behavior.

Just before the first pitch of the game against the Braves, the three were at a picnic table in an open-air area overlooking Tony Gwynn Drive.

“She seemed happy, laughing,” the witness said of the mother. The man was standing next to the rail, and the woman stood up on the table’s bench with the boy in her arms and started jumping, the witness told NBC7.

“She lost her balance and fell off the bench. I remarked to my son, ‘Oh my gosh, she almost fell.’ … About 30 seconds or a minute later, she jumped back up and did it again, facing the man as she jumped with the baby. I remember saying, ‘I can’t believe she’s doing that again.’ And then she was gone.”

“There were no screams. It was just eerily quiet,” the witness said. The shocked onlookers heard the sound of the impact.

The pair were pronounced dead at the scene.

Police had earlier said the two fell from an elevated walkway connecting the stadium to a parking lot, but later said they had been on the stadium concourse.

A stadium worker told NBC7 that the tables have now been moved away from the 45-inch-tall railing.

In the early stages of the investigation, police told the San Diego Union-Tribune it was too soon to know whether the fall was accidental or intentional but that it “appeared to be suspicious.”

In April of this year, a San Diego woman was killed when a man who jumped from a parking garage near Petco Stadium landed on her. The man died as well.