Greenburgh Town Supervisor Paul Feiner is calling on the state to conduct an independent investigation of what caused a crane to collapse Tuesday on the Tappan Zee Bridge.

The crane at the construction site of the new bridge fell across the old bridge Tuesday, closing the span for over five hours.

The southernmost lane on the Westchester-bound side suffered the most damage. Part of the guardrail was knocked out, and the weight of the crane smashed a hole through the decking.

Repairs to the span are expected to last several days.

In addition to repair crews, investigators will be focusing on what exactly caused the crane to suddenly topple over just before noon Tuesday.

Gov. Andrew Cuomo said a full investigation is being conducted, but exactly what is being done remains a mystery.

News 12 has learned that the crane was built recently by Manitowoc Cranes, based in the Harrisburg, Pennsylvania suburbs. Manitowoc didn't return calls, so News 12 went to the offices of the Tappan Zee Constructors.

Tappan Zee Constructors released a statement late Wednesday afternoon saying that the case remains under investigation, but sources close to the investigation say that they do inspect the cranes every day.

This isn't Tappan Zee Constructors’ first safety issue. The OSHA website shows three violations totaling $9,000 in fines, but none of those incidents involved cranes.

Feiner said that this is one of the reasons he wants a full investigation.

“We have to make sure we double-check to make sure there's controls and oversight of the contractors and subcontractors working on the bridge,” he says.