Tommy Macias, 51, said in a now-deleted Facebook post that a couple of a weeks after he went out, he got tested for coronavirus on June 15 and got a positive result on June 18.

"Because of my stupidity I put my mom and sisters and my family's health in jeopardy," he wrote on June 20. "This has been a very painful experience."

He urged others to wear a mask and practice social distancing if they have to go out. Macias thanked those who brought him food and supported him.

"Hopefully with God's help," he added, "I'll be able to survive this."

He died on June 21. An official from the Riverside County Office of Vital Records confirmed to multiple news outlets that Macias died from COVID-19.

Macias, a truck driver who suffered from diabetes, was especially vulnerable to the virus and had barely gone out before the barbecue, his brother-in-law Gustavo Lopez told CNN. But when restrictions lifted in California, "he felt free" Lopez said.

Gov. Gavin Newsom said Wednesday that 19 counties in California would take a major step back in reopening plans as the state grapples with rising positive tests and deaths from the coronavirus. He expects the rollback to last at least three weeks.

Lopez said about a dozen people who attended the party tested positive.

Lopez's daughter, Danielle, told USA TODAY that after the party, a friend called her uncle and said he knew he had coronavirus before attending the get-together, but decided to go anyway without a mask because he wasn't showing symptoms.

"We don't want to blame anybody," she said, noting that her uncle should've stayed home as well. "But it's difficult to not be angry at this person who if they had just worn a mask, just stayed home ...my uncle would probably still be here with us."

Lopez said when her uncle started feeling sick, he thought it had something to do with his diabetes. Family members said he had trouble breathing and was rushed to the hospital where he died hours after being put on a ventilator.

The family will be holding a funeral service on July 10, according to Lopez. She said on Facebook that masks and social distancing would be required and a teleconference option would also be available.

"We’re having a hard time grasping that any of this is actually happening," she said. "It hasn't fully set in that he’s gone."