He is the first identified victim of the rampage.
At least 12 people died and approximately 10 more were shot after a gunman threw smoke grenades and opened fire at the Borderline Bar & Grill in Thousand Oaks, west of Los Angeles, according to ABC News and the Los Angeles Times.
The shooter also died in the attack, though it is unclear how.
Gunfire was first reported about 11:20 p.m, Ventura County Sheriff Geoff Dean told reporters. Helus was one of the first responders at the scene, three minutes later, Dean said. He was shot multiple times as he went through the front door.
“He went into save lives, to save other people,” Dean said, according to CNN. “He was totally committed, he gave his all, and tonight, as I told his wife, he died a hero.”
The sheriff reportedly choked up describing his colleague, who leaves behind a wife and son.
Before he headed into the building, Helus called his family, according to the Times.
“It’s so tragic losing Ron,” Sheriff Dean said. “We go to the gym together, work out together. It’s horrific and terrible and it saddens our hearts.”
“He died a hero, because he went in to save lives,” Dean said of Helus, according to the Post.
“Great bravery shown by police,” President Donald Trump tweeted early Thursday. “California Highway Patrol was on scene within 3 minutes, with first officer to enter shot numerous times. That Sheriff’s Sergeant died in the hospital. God bless all of the victims and families of the victims. Thank you to Law Enforcement.”
The bar was hosting a “College Country Night” on the night of the shooting and, according to the Times, hundreds of people were in attendance.
“It was chaos, people jumping out of windows, hopping over gates and just trying to get out,” Nick Steinwender, who had friends inside, told local TV station KABC. “From what I heard, the gunman started shooting at the front desk. … Students were hiding in the attics, bathrooms and stuff like that.”
“It’s a horrific incident,” Sheriff Dean said. “It’s part of the horrors that are happening in our country and everywhere, and I think it’s impossible to put any logic or sense to the senseless.”