Construction site deaths fell a whopping 84 percent from last year as the city instituted tougher safety rules and building slowed due to the recession, officials said yesterday.

Three fatal construction accidents were reported last year, compared with 19 deaths during 2008 — including nine who died as a result of two horrific crane accidents on the East Side of Manhattan.

The accidents prompted a sweeping review of safety standards that gave the Buildings Department expanded enforcement powers, while requiring more extensive worker training.

“We have been working to change the culture of the construction industry – to put public safety ahead of profit – and our message is being heard,” said Buildings Commissioner Robert LiMandri.

Fatal construction accidents had been rising steadily in connection with the city’s building boom, which has since cooled dramatically.