BUFFALO, N.Y. (WIVB) — Two children were among the three people killed after they went over Niagara Falls on Monday night, according to New York Park Police.

Police responded to the area of Goat Island around 9 p.m. Monday. Investigators determined that 33-year-old Chaianti Means and her two children, a 9-year-old and a 5-month old, crossed over the safety guard rail on Luna Island and went over the Falls.

Luna Island is a small island between the American Falls and Bridal Veil Falls that, along with the Horseshoe Falls, make up the popular tourist draw.

Police said the incident was “intentional in nature, though the circumstances remain under investigation.”

Search and rescue efforts were not successful. Authorities are using unmanned aircraft and underwater units in the investigation.

All three killed were residents of Niagara Falls.

EDITOR’S NOTE — This story includes discussion of suicide. If you or someone you know needs help, the national suicide and crisis lifeline in the U.S. is available by calling or texting 988.

The Associated Press contributed to this report.