ORLANDO, Fla. (CBS/AP) -- A disgruntled former employee opened fire Monday inside a Florida awning factory, killing five workers before killing himself, authorities said.
Sheriff Jerry Demings identified the shooter as John Robert Neumann Jr., a 45-year-old Army veteran who lived alone and did not appear to be a member of any type of subversive or terrorist organization.
"We are all on heightened alert from the tragic incidents across the globe," the sheriff's office said on Twitter, two days after a vehicle and knife attack launched by three men in London Saturday night that killed seven people and injured dozens. "We cannot connect this incident to any global terrorism."
Neumann had been fired in April. He was not charged when he was accused of battering the co-worker in June 2014, and his previous criminal record was otherwise minor - marijuana possession and driving under the influence, the sheriff said. The co-worker he allegedly beat up three years ago was not among the victims Monday, the sheriff added.
Police found three men and one woman dead at the scene, Demings said. A fourth man was taken to a hospital, where he died.
Demings identified the victims as Kevin Clark, 53; Kevin Lawson, 46; Brenda Motanez-Crespo, 44; Jeffrey Roberts, 57; and Robert Snyder, 69.
Seven people survived the shooting and were being interviewed by police.
Shelley Adams said her sister, Sheila McIntyre, called her from the company's bathroom during the shooting and kept repeating, "My boss is dead. My boss is dead."
"She is very distraught, very emotional," Adams told CBS Orlando affiliate WKMG-TV.
State and federal law enforcement officers converged on the industrial park in Orlando shortly after 8 a.m. after a woman ran from the awning business, saying the gunman had told her to leave. She used the phone of a tile business across the street to call 911, said Yamaris Gomez, the tile store's owner.
"All she kept saying was he was holding a gun and told her to get out," Gomez said.
The sheriff said officers were dispatched within 45 seconds and arrived two minutes later. The FBI also responded, said Ron Hopper, who runs the FBI's Orlando office.
After 9 a.m., the sheriff's office said on Twitter that there were "multiple fatalities."
Special Agent Danny Banks of the Florida Department of Law Enforcement said that while five people were killed, "seven others' lives were saved due to the quick actions of the officers who arrived on the scene today."
Banks said authorities had no reports of any specific threats the gunman made to people at the company or anyone else. He said the attack shows why people need to alert authorities if they learn of anything that could lead to violence.
"If people see something that seems abnormal, they need to say something," Orange County Mayor Teresa Jacobs added.
Fiamma Inc. calls itself one of the largest manufacturers of awnings for camper vans, motor coaches and sport utility vehicles.
Gov. Rick Scott said he had been briefed by law enforcement and that he and his wife, Ann, were "praying for the families who lost loved ones today."