LA CANADA FLINTRIDGE (CBS) — Authorities Tuesday were investigating the drowning death of a 6-year-old girl.

Emily Su was pronounced dead at a local hospital after she drowned in a swimming pool in the 4900 block of Indianola Way at 7:20 p.m. Monday, authorities said.

READ MORE: Fontana Softball Coach Osbaldo Gonzalez Arrested For Allegedly Molesting 3 Of His Players

Su had been playing with a 5-year-old girl at a block party when that child came into the house soaking wet. Su’s 14-year-old brother then jumped in the pool to rescue her, but attempts to revive her were unsuccessful.

One parent told KNX 1070’s Jon Baird she was stunned by the news.

READ MORE: Petition Launched To Help Save Hollywood's Cinerama Dome

“I’m really shocked that this has happened,” she said. “I mean a death, that’s huge in La Canada, for a little kid, that’s huge.”

Baird reports there was apparently a fence around the pool, but it was damaged.

MORE NEWS: Jauhar Tajuddin Shuaib Of Irvine Faces Hate Crime Charge After Allegedly Punching Woman, Hurling Racial Comments At Her

The Los Angeles County Coroner’s office was expected to conduct an autopsy Tuesday.