The male suspect, an employee of the Valley Transportation Authority (VTA), is dead, Deputy Russell Davis of the Santa Clara County Sheriff’s Office said.
Authorities received 911 calls at about 6.34am on Wednesday (local time) saying there were shots fired near a VTA control centre, a hub that stores multiple light rail trains and a maintenance yard, Mr Davis said.
VTA employees were among the victims. Multiple law enforcement agencies and Fire Department personnel responded to the incident using their “active shooter protocol,” Mr Davis said.
“While shots were still being fired, our teams were entering the building,” Santa Clara County Sheriff Laurie Smith said.
VTA Board Chairperson Glenn Hendricks said the shooting occurred in the rail yard – not the operations control centre – at a time when light rail was starting up for the day. The yard is where the VTA vehicles are maintained and dispatched.
“A horrible tragedy has happened today, and our thoughts and love goes out to the VTA family, the organisation and what they’ve had to go through,” Mr Hendricks said.
There are multiple active scenes connected to the investigation into the shooting, according to San Jose Fire spokeswoman Erica Ray.
Overhead video of the VTA rail yard shows a large law enforcement presence on the scene as well as several ambulances.
San Jose Mayor Sam Liccardo, referred to the shooting as a very dark moment for the city.
“This is a horrific day for our city, it’s a tragic day for our VTA family,” Mr Liccardo said. “We know that so many are feeling deeply this loss of their loved ones and their friends.”