This crane toppled over around 9 a.m. Friday at a construction site near the waterfront in Saint John. (CBC)

A 200-tonne industrial crane fell onto a street in Saint John on Friday, smashing through a fence and sending the crane operator to hospital.

The accident happened at about 9 a.m. at a construction site near the waterfront.

Diesel fuel and hydraulic fluid leaked out of the large yellow machine, which had its motor running for hours after the accident.

The crane destroyed a fence surrounding a parking lot and scattered debris, damaging nearby cars. The crane was being used to move large cylinders that are part of a wind turbine.

The crane, owned by Irving Equipment, was operating at the port's marine terminal on Broadview Avenue, at the foot of Charlotte Street.

Mark Gillan, the deputy fire chief in Saint John, said the crane was damaged but the accident could have been much worse.

"There has been a fair amount of luck involved, from the standpoint of we have had a crane that has come over onto the street," Gillan said.

"It has not struck any civilians or any passersby that would be using the street in their vehicles."

Irving Equipment spokesman Geoff Britt said the operator was in the lower cab at the time and managed to get out on his own. He was taken to hospital and released after being treated for a cut to his hand.

Britt said the man was a 36-year veteran with 10 years' experience on this type of crane.

Gillan said Saint John police and WorkSafeNB have been called in to investigate the incident. They are still trying to figure out precisely what caused the machine to fall.

"The early reports indicate that the crane operator was at the time repositioning the piece of apparatus and at that point there was some sort of failure and it toppled over onto the street," Gillan said.

Loud bang

The crane operator was treated at Saint John Regional Hospital. (CBC)

Witnesses at a nearby warehouse said they rushed outside when they heard a loud bang.

Danny Johnson, who was working at the nearby warehouse when the crane fell over, didn't see it fall but he heard it.

"It was pretty loud," Johnson said. "We came over to offer a hand if we could and hope for the best for the driver."

A second, 500-tonne crane will be used to raise the fallen machinery. Technical officials from J.D. Irving Ltd. were also called in to help get the crane back upright.