(ABC News)

They were among the youngest at the Sikh temple near Milwaukee that deadly Sunday - and some of the bravest.

Amanat Singh, 9, and her brother, Abhay Singh, 11, were playing outside when they heard gunshots that sounded like fireworks. It was the start of the incident that eventually claimed six lives before the gunman shot himself.

"We saw a guy," Amanat said. "He got out of a cab and he fast-walked and hit two people who were getting into their car."

They children didn't hesitate. They ran into the temple to sound the alarm.

"As soon as we got in the kitchen, I started yelling," Abhay said. "I'm like: There's a guy with a gun! Hide! Hide!

Amanat said she feared, "that he's going to kill everyone."

The siblings were able to warn more than a dozen people to run and hide.

Harban Singh Farwaha was one of them.

"They saved my life," Farwaha said.

He added that they also saved the lives of "my wife, my daughter-in-law and many people."

Amanat and Abhay are happy they were able to do that. Amanat even said she feels like a hero.

"I feel proud because I saved lots of lives," she said.

Even so, she and her brother wish they could have done more.