Five people have been killed in a shooting at an Orlando industrial estate, police in Florida say.
They said the gunman was a former employee at a store on the estate who was sacked in April. He took his own life after the killings.
There is no suggestion the killer was a member of a subversive or terrorist organisation, police said.
The shooting came a week before the first anniversary of the Pulse nightclub shooting in the city.
Forty-nine people were killed in that incident.
Orange County Sheriff Jerry Demings said police had arrived at the scene of the shooting to find four people dead. A fifth employee died while being taken to hospital.
The sheriff said the killings were probably linked to a workplace dispute. They occurred at a business that makes awnings for recreational vehicles.
The gunman, 54, has not been named by police. All of the dead were employees at the firm.
The assailant is believed to have attacked a member of staff in 2014, although no charges were filed, Mr Demings said.
In a statement , Florida Governor Rick Scott condemned a "senseless act of violence".
"Over the past year, the Orlando community has been challenged like never before," he said.
In last June's attack, the deadliest mass shooting in modern US history, gunman Omar Mateen killed 49 people and injured dozens more at a gay nightclub before being shot dead by police.