At least four people were killed, including the suspected gunman, when a disgruntled United Parcel Service Inc employee opened fire at a company facility in San Francisco, two local TV news stations reported.After firing on co-workers, the suspect turned a gun on himself when confronted by police, according to NBC Bay Area and ABC 7. He later died at an area hospital, they said, citing law enforcement sources.San Francisco police said the building was secure but offered no immediate information on victims.Live video showed a massive police presence near the facility that employs 350, with employees being led out and embracing each other on the sidewalk outside."UPS confirms there was an incident involving employees within the company’s facility in San Francisco earlier this morning," the company said in a statement."Local law enforcement have control of the facility and are conducting an investigation. We cannot provide information as to the identity of persons involved at this time, pending the police investigation," the statement said.Victims were taken to the Priscilla Chan and Mark Zuckerberg San Francisco General Hospital, spokesman Brent Andrew said. He said he could not say how many patients were taken to the hospital or give their conditions.