A gunman that opened fire in a Californian church killed one person and left four critically injured before the pastor was able to take him down.

After a gunman walked into a Laguna Woods, California Presbyterian church yesterday, Pastor Billy Chang decided to bravely take charge of the situation and hit the gunman with a chair as the shooter paused to reload his gun.

The congregation met after the Sunday morning service to have lunch when the gunman entered the building holding two handguns. 

The gunman, in his 60s, began shooting the roughly 40 congregants of the Taiwanese Geneva Presbyterian Church and ended up killing one person and injuring five with four of those in critical condition, according to the Los Angeles Times. When the gunman moved to reload, the pastor took him down and the rest of the people hog-tied him until the police showed up. 

The luncheon was meant to be a celebration to honour a former pastor of the Taiwanese congregation, according to The Christian Post.

"There is a lot of grief and disbelief among the congregation," says Yorba Linda Councilwoman Peggy Huang, who has family members belonging to the church. "This was supposed to be a joyous occasion."

The police on the scene were surprised by the actions of the pastor and congregation. 

"That group of churchgoers displayed what we believe is exceptional heroism and bravery," says Undersheriff Jeff Hallock. "It’s safe to say that had they not intervened, this situation could have been much worse."

The local police have arrested the gunman, and at this point are unaware of what caused the violent act. 

"Our small Taiwanese congregation has put out love and kindness into the surrounding community for generations," says the people of the church on a GoFundMe page. "During this time, our church, the victims, and their families need to focus on recovering from this tragedy."