He used the event as a platform to remind engineers of the challenges they faced in ensuring a safer working environment.
"We still kill more than 70 workers per year. There’s also a considerably large problem with occupational ill health," said Williams.
Given that the construction industry employs 10% of Britain’s working population, 70 deaths per year may not sound like a large number.
But Williams was quite clear: he reminded the audience at One Great George Street that that there was no room for complacency, even if the industry was completely accident-free.
This message was particularly pertinent as it was revealed last week that the fatal accident rate in the construction industry had actually risen. In 2006/07 there were 77 fatal accidents in construction, the highest total for five years and a 28% rise on the previous year.
However, this rise was confined to the refurbishment and home building sector and Williams was clear about where HSE’s efforts needed to be focused.
"The cascade [of health and safety best practice] from large to small projects is only taking us so far," he said.
While an excellent health and safety record is now always the top priority for large construction firms, Williams said that the message had still failed to trickle down to small and medium-sized firms. It is on their sites that between 60% and 75% of all accidents occur.
However, Williams said there were a number of initiatives aimed at rectifying this situation, including the Working World Together scheme.
"There is a whole range of activities aimed at the small sector," said Williams.
"Working Well Together sees large contractors and designers work with HSE to invite small firms to witness how safety onsite can be."
Despite Williams' praise for large engineering firms' leadership in health and safety, he did raise concerns about a few anomalies in the general downward trend in construction accident rates.
"I’m slightly nervous that industry has taken its eye off the ball," said Williams.
"Over the last couple of years there have been substantial fires, high profile and spectacular tower crane collapses, scaffold collapses and building collapses, particularly the one [that took place] recently in London.
"All of those had potential to kill more than one person. We need to really focus with the events that have had the potential to kill tens of people."
Of course, the introduction of the CDM regulations, compulsory this April, was intended to be a giant leap that will eventually lead to construction sites being a death-free working environment.
To make the most of the regulations, said Williams, engineers must take advantage of what he saw as their streamlined and flexible nature.
"For example, anyone can fulfil the various roles in the regulations," he said.
"Take advantage of that flexibility."
The practicality of needing only someone who clearly understands the regulations to be a CDM project coordinator, rather than a health and safety super-specialist, should also be extended to safety documentation, added Williams.
"Make CDM work for you by cutting bureaucratic processes – focus on planning and management instead of the plan," said Williams.
"A simple site safety plan with finger marks and mud on it is far more favourable than a Rolls Royce of a document that is filed nicely in the office and never seen."