JACKSONVILLE, Fla. -- Two giant container cranes on Blount Island tipped over during a thunderstorm Wednesday afternoon, leaving a pile of twisted metal on the ground and millions of dollars in damages.

Heavy Winds Suspected Cause Of Crane Collapse

The cranes collapsed at about 3:30 p.m., shutting down most traffic near the port, according to Jacksonville Port Authorities officials.

"It shut down our incoming gate. The trucks were being diverted, either turned around totally or they're queuing up on the side and waiting for the gate to reopen," said Jaxport spokeswoman Nancy Rubin.

The gate was reopened to ground traffic at about 5 p.m. The waterway was also open for marine traffic.

Although Jaxport officials confirmed that strong storms with high winds were moving through the area when the more than 200-feet tall cranes collapsed, the exact cause of the collapses remains under investigation.

"This is one of those events that on appearance to us today is very, very unique, very isolated, and I think in large part driven by what we believe was just wind sheer," said seaport security director Charles White.

Investigators said they would not know for sure whether wind caused the collapses for a few days as they start removing the fallen cranes.

"They're always secure because when they're not working, the brakes are in place. So, they're always secured on the dock and they're supposed to withstand a very high wind tolerance," said terminal director Victoria Robas.

The cranes -- valued at $6 mill each -- operate on a rail system similar to a railroad track. Channel 4 was told one of the cranes on the rail was several yards from the others and was possibly blown along the track causing it to hit the second crane before both collapsed.

"I would liken it to a locomotive train. It is on rail and it has steel wheels just like you would see on a train car, and that's how it move up and down the dock," White said.

Investigators said the velocity of the wind had to have been enormous to move the cranes along the track.

"Weather-related event … it's just kind of like a lot of things coming together as almost the perfect storm," White said.

Nobody was on either crane when they collapsed and no one was injured during the incident.

The crane collapse was not expected to interfere with other port operations.