Members of the St. Louis Metropolitan Police Department SWAT team shot and killed a 21-year-old man Wednesday morning.

It happened at around 11:20 AM on South Kingshighway, just east of the St. Louis Hills neighborhood. It was an emotional scene just outside the house that afternoon. Family members say Isaiah Hammett is dead.

"The cops came in and killed my son," Gina Torres said. "I needed my son and I feel like dying right now."

Dawn Atwell says she doesn't understand why her grandson's life had to end.

"I'm feeling totally devastated that I don't know what has happened to my grandson over there," Atwell said.

Police say there is an investigation into narcotics and illegal firearms involving the 21-year-old. Eight SWAT officers went to the house Wednesday to execute a search warrant. Interim police chief Lawrence O'Toole says the officers announced their presence and threw a flash-bang device into the house.

"As they entered the residence, they came upon heavy fire," O'Toole said.

He says the 21-year-old immediately began firing shots at officers with an assault rifle and officers returned fire, striking and killing the man. Investigators later recovered the rifle.

"Our officers frequently encounter high power assault rifles," O'Toole said. "Extremely dangerous business. Our SWAT officers today did a fantastic job under fire. Very heroic and that's part of this business but we're dealing with very violent offenders, very violent people."

Dennis Torres says Hammett was his caretaker. The 71-year-old U.S. Army veteran says he was the only other person home at the time of the shooting. He says he was in bed when officers arrived and Hammett tried to protect him from the bullets.

"I just heard a bunch of gunshots, my grandson coming in, put me on the - took me out of bed, put me on the floor," Torres said. "More shots was being fired ... The next thing I know, he's lying on the ground dead."

Although Torres says there were at least three guns in the home, the family believes Hammett did not fire first.

"For no reason," Gina Torres said. "They shot my son to death."

Police say there are surveillance cameras outside the house and the 21-year-old may have known the SWAT team was approaching. The Force Investigative Unit is handling the investigation.