The $6 million (5.4 million euro) settlement reached Wednesday is the largest payout involving a single worker death in California, prosecutors said.

Plant worker Jose Melena, 62, had been loading pallets of canned tuna inside a walk-in oven when a co-worker, thinking the man was on a bathroom break, shut the door and switched on the heat. Two hours later Melena's body was discovered after being cooked to death in the 132-degree Celsius heat.

"This is the worst circumstances of death I have ever, ever witnessed," said Hoon Chun, a veteran homicide prosecutor of more than two decades. "I think any person would prefer to be - if they had to die some way - would prefer to be shot or stabbed than to be slowly cooked in an oven. "

In a rare prosecution of a workplace fatality the plant operations director and former safety manager were each charged with three counts of violating state occupational health and safety regulations and causing a death.

The managers were sentenced to a mixture of probation, community service work and fines in connection with the October 11, 2012, death.

Restitution paid to family

Melena's family will receive $1.5 million under the settlement, and it does not prevent them from also suing the company or receiving workers' compensation funds.

"Certainly, nothing will bring back our dad, and our mom will not have her husband back, but much can be done to ensure this terrible accident does not happen again," the family said in a statement.

The San Diego-based company has been ordered to make a $3 million upgrade to its plant to prevent a repeat of the horrific accident. But it is appealing $74,000 in fines by the state's occupational safety agency for failing to properly assess employee danger.

"We will never forget the unfathomable loss of our colleague Jose Melena and we are committed to ensuring that employee safety remains a top priority at all our facilities," the company, owned by private equity firm Lion Capital LLP, said in a statement.

Criminal prosecutions of workplace violations are fairly uncommon in the US - even those that cause deaths. Of 189 fatality investigations opened by the state of California in 2013, only 29 were referred to prosecutors. Charges were only filed in 14 cases that year, according to state records.

jar/gsw (AFP, AP, Reuters)