A United States grandfather who died after eating McDonald’s food contaminated with E. Coli was not warned of the danger after he became sick — and returned for a second Quarter Pounder before he died.

JC Smith of Colorado was one of 90 people to fall ill after eating McDonald’s Quarter Pounders in the US, after the onions in the burgers were contaminated with E. Coli, a bacteria that can cause diarrhoea and fever.

Smith’s heartbroken family have spoken out, saying “he put his trust in these restaurants” and just wanted to enjoy a simple meal with his wife.

“All we want is our dad back,” his daughter Debbie Bonnell told CBS News.

Of the 90 cases, 26 came from Colorado. The state is also home to the distribution centre believed to be the source of the onions.

Smith and his wife were regular visitors to McDonald’s and always enjoyed the same thing — a Quarter Pounder.

But he fell ill after a visit in late September and was hospitalised.

JC Smith, US man who died after eating McDonald's food contaminated with E. Coli.

Tests showed the presence of E. Coli and he was treated for four days before being judged fit to be discharged.

Debbie Bonnell told CBS she was quizzed by health officials as her father left the hospital.

“(The health department worker) asked ‘Where did my parents eat?’ because there was some type of outbreak,” Bonnell said. “But they were not going to say where yet.”

The family was still in the dark as to the source of the infection and Smith then made the fateful decision to return to McDonald’s — for another Quarter Pounder.

The symptoms returned and he was hospitalised again. He died on October 20.

‘Excruciating pain’ and a wife’s guilt

Doris Smith called her daughter on October 3, concerned about her father’s health.

Bonnell rushed over and found her dad “so weak he couldn’t walk”.

Hospital treatment followed, but the second time was much worse.

“We watched my daddy have excruciating pain for many days — thrashing his arms and legs around. It was very hard,” Bonnell said.

A McDonald's Quarter Pounder.

Although JC Smith’s decision to eat Quarter Pounders at that Colorado McDonald’s proved fatal, his wife escaped without injury.

She is not a fan of onions, she told CBS.

“I raked mine off and gave some to him,” Doris said, admitting she feels guilt for her actions.

JC Smith’s grandson Jim said the family was speaking out to protect others.

“If you are out there in that line of work … and you lose a level of concern or become complacent, accidents happen. Then you’re going to be held accountable. And when you’re talking about taking people’s loved ones and changing their life permanently, others need to know,” he said.

JC Smith’s family are yet to take any legal action — they say they just want him back.