The store remained closed to customers more than 12 hours after police were called to the area of Sierra and Santa Ana avenues regarding a man in the road who appeared to be trying to get hit by a car.
When officers showed up around 6 p.m. Monday, police say the man ran into the store and grabbed an edged weapon before they opened fire.
A man who did not wish to be on camera described what happened in those moments.
"You know, I see people screaming, running out... Picking up their kids and stuff like that. Some people froze," he said. "My daughter was going to come with me last night. Thank God she didn't."
Man fatally shot inside Fontana Home Depot after arming himself inside store
Authorities say the situation happened quickly and there was no time to evacuate the store.
"He didn't listen. The subject armed himself with a hole-punch saw, which is a sharp edged weapon which could hurt the civilians in the store or the officers," said Sgt. Nathan Weiske.
Officers shot the man, who died at the scene.
"Scary man. You see these things happen all over the country. Just scary," the witness told Eyewitness News.
A coroner's van was seen taking the suspect's body away around 5:30 a.m. Tuesday. He has not been identified.
Jimmy Gordon, who lives in Jurupa Valley, goes to the store often and says he doesn't feel safe in the area.
"Daylight yes, nighttime, no. After dark, I won't come," he said.
No officers or customers were hurt during Monday's shooting. The investigation is ongoing.