A 30-year-old dad-of-four died just hours after waking up complaining he couldn't breathe.
Mark Barton's devastated family say the former security guard died suddenly at home before he was able to reach hospital.
His family claim that Mark had suffered a blood clot that traveled up to his lungs, restricting his breathing.
Just the previous day, they had all been celebrating the birthdays of two of their children, the Liverpool Echo reports.
Mark and his wife Lisa from Hutyon, Merseyside, celebrated their first wedding anniversary last month after they were married back in August 2018.
Sister-in-law, Lauren Rose, said: "Mark had been feeling a bit sick but he didn't feel the need to go to the doctors.
"Then he woke up one morning saying that he couldn't breathe. He died at home.
"It was completely out of the blue. He was fine at the party the night before."
She described her brother-in-law as well known and popular.
Paul Williams, Mark's brother, said he his brother would go above and beyond to help people.
He said: "He would do anything for anyone. He'd stop what he was doing to do what he could to help others.
"He used to volunteer at the local church foodbank."
Paul said that his brother's death came out of nowhere and with little warning.
He said: "All of a sudden he just passed away, out of nowhere. He died from a blood clot which travelled all the way up to his lungs.
"Were were all extremely shocked. It was so sudden."
