On Tuesday night, a gunman killed at least six people at a Walmart in Chesapeake, Virginia, reports NBC News. Four additional people were taken to a hospital.

According to Chesapeake Police Chief Mark Solesky, the shooter was an employee at the store. Solesky also noted that the gunman died from a self-inflicted gunshot wound.

Officials have swept the shooter's home for evidence. His identity has not been revealed because his next of kin has not been notified.

No motive has been determined.

said “I am devastated by the senseless act of violence that took place late last night in our city,” Mayor Rick W. West in a statement posted on the city’s Twitter account Wednesday. “Chesapeake is a tight-knit community and we are all shaken by this news.”

“We are shocked at this tragic event at our Chesapeake, Virginia store. We’re praying for those impacted, the community, and our associates,” Walmart said in an issued statement. “We’re working closely with law enforcement, and we are focused on supporting our associates.”

Briana Tyler, a Walmart employee, described the horrific scene on ABC’s Good Morning America. She said that workers gathered in the store’s break room as they were preparing for their shifts.

“I looked up, and my manager just opened the door and he just opened fire,” she said, adding that “multiple people” dropped to the floor.

“He didn’t say a word, he didn’t say anything at all,” she added.

Joetta Jeffery told CNN that she received text messages from her mother who was trapped inside the store during the shooting.

“I’m crying, I’m shaking,” Jeffery said. “I had just talked to her about buying turkeys for Thanksgiving, then this text came in.”

Her mother, Betsy Umphlett, was not injured.

Law enforcement officials have asked people to refrain from visiting the store during the investigation.

“Our first responders are well-trained and prepared to respond; please give them space to do so,” the city said in a tweet.

In an official statement, the NAACP called on Congress to act as the country is reeling from another mass shooting.

"Another day in America, another unspeakable tragedy, leaving family members with broken hearts and empty chairs at their holiday gatherings. So far this year, there have been over 600 mass shootings, with seven taking place in the last seven days alone. One thing is clear—Congressional legislators must do their job and pass common-sense reforms that will save American lives," the statement read.

"Congress, do your job. Where are we even safe anymore? Churches? Synagogues? Clubs? Concerts? Schools? Walmarts? When is it enough?" the statement continued.

The mass shooting at Walmart comes just three days after a shooter opened fire at Club Q, a gay nightclub in Colorado, killing five people and wounding 17. 

According to the Gun Violence Archive, there has been an average of 13 mass shootings a week so far