With Friday's collapse, crane failures have now killed at least a dozen people in the city in eight years. NY1's Michael Herzenberg filed the following report.

More than 300 cranes operate in the city every day, almost always without incident. But a series of crane failures have left New Yorkers wondering about their safety.

"I want people to hear me loud and clear. We've had some construction site incidents that are very troubling. More and more inspectors are going to get on top of that," said Mayor Bill de Blasio.

In 2008, a 19-story crane toppled on the East Side, killing seven people. An investigation found that a city inspector had falsified records and a contractor used a tattered sling to secure the crane, but was found not guilty of manslaughter.

Months later, on the Upper East Side, two construction workers died in a crane collapse.

The mayor tried to reassure New Yorkers Friday, saying there had been no crane collapses since 2008. But at least two people have died in crane failures since then, in 2012 and 2015.

The crane in Friday's accident is owned by Bay Crane and operated by Galasso Truck and Rigging. Ten people were hurt when a cable snapped on a Bay Crane at Madison and 39th Street last May, and in 2010, a Bay Crane crashed into a Lower Manhattan building, but no one one was injured.

Officials say it appears the necessary permits were in order for the crane that malfunctioned Friday. The city inspected the device on Thursday.

"So at this point, we believe they've been doing their work effectively," de Blasio said.

City Comptroller Scott Stringer charges that the Buildings Department has failed to implement many of the safety recommendations made by a consultant in a $6 million study five years ago.

"Maybe we should be doing more to ensure that these accidents don't happen," Stringer said.

After the 2008 deaths, the state stiffened penalties on crane inspectors who falsify records, and the city strengthened inspections and required more training for crane operators. The mayor is now promising additional changes if investigations of Friday's accident uncover new problems.