Foundations laid by Lord Ballyedmond at his veterinary medicine firm Norbrook will ensure its success in the future, the company's director Sir Roy McNulty has said.
Sir Roy, a friend of the high-profile industrialist for more than three decades, said he was in shock at the tragedy, and had been in touch with the Haughey family to offer his sympathy.
"It's both the fact that it has happened, and that it has happened in such a dreadful way," he said.
Northern Ireland-born Sir Roy, who said he had spoken to Mr Haughey just last week and was due to meet up with him soon, got to know the businessman in the early days of Norbrook
"Whenever I met him in about the mid-1970s, it only had about 10 or 12 employees. Now it has at least 1,500, and it's been a tremendous boon for the Newry area and beyond," he told the Belfast Telegraph.
The former Shorts chairman said Norbrook – which employs 1,892 people and made pre-tax profits of £21m in its most recent accounts – would continue to prosper. "Great people make great companies and great companies go on well after their founders have gone."
He is one of just four Norbrook directors along with Lord Ballyedmond, his son James and long-term finance director Martin Patrick Murdock.
Sir Roy said: "No matter how brilliant Eddie was – and he was a brilliant entrepreneur – one person doesn't make a company of that size.
"But the foundations he laid will take the company forward quite strongly. He was a real entrepreneur. I have seldom known any being with so many good ideas in profusion.
"He always had a very clear vision of where he wanted to get to – often way beyond what anyone else could see – but he did get there."
Sir Roy said it was too early to speculate on who might succeed Lord Ballyedmond but said another son, Ed, was also involved in the company.
According to Companies House records, James (33), who is a qualified medical doctor, was appointed director last August.
Economist John Simpson said the vacancy which now exists at the top of Norbrook would be closely watched. "They will need to find someone who will have the same effect and the same management style.
"There has been no obvious successor in the public eye so it will be of interest what the family now decides to do."
He said there was a parallel with another pharmaceutical company, Almac in Craigavon, which had continued to thrive after the death of its well-regarded founder, Sir Allen McClay, in 2010.
He said: "Allen was a very strong force at Almac but never pretended to be on top of the technology, even though he did manage the firm. But Eddie Haughey was on top of product development. The gap left by his departure is bigger than that left by Allen in his company."