CFB SHEARWATER, N.S. -- Canada's fleet of Sea King helicopters has been indefinitely grounded after one of them tipped forward and smashed its five rotor blades on the tarmac at Canadian Forces Base Shearwater in Halifax, the military said Tuesday.

The wing commander at the military base said nobody was hurt in Monday night's accident, including the four air crew members who were aboard.

"We're suspending all flying operations until we get an indication of what's going on and a higher authority has made a call on how we're going to proceed with flying the Sea King in the next couple of days," Lt.-Col. James Hawthorne told a news conference.

The chopper landed after a five-hour training mission, taxied to a hangar, stopped and tipped forward while the rotors were still spinning, causing each of the 10-metre blades to break into pieces of flying debris that dented walls and broke glass on surrounding buildings, Hawthorne said.

He said the pilot told him that the accident unfolded quickly.

"He said it's the fastest thing he'd ever seen occur in a helicopter," Hawthorne said. "It caught him by surprise just like it caught everybody by surprise."

Hawthorne said the damage to the helicopter is extensive and the military will have to assess whether it can continue flying.

Three military investigators have been assigned to determine what happened.

The are 25 Sea King helicopters in the military's fleet, two of which are kept grounded to train maintenance crew. Another two are on overseas missions, but their work will be suspended until the flying restrictions have been lifted, said navy Lt. Len Hickey, a spokesman for CFB Shearwater.

Attempts by the federal government to replace the 50-year-old fleet of Sea Kings have been repeatedly delayed.

The military is still waiting for new helicopters from Sikorsky Aircraft Corp., which was selected nine years ago to supply 28 helicopters.

Hawthorne said he couldn't answer questions on when the replacement choppers would arrive, but he added that he doesn't believe the age of the Sea Kings was a factor in the accident.

"The Sea King has provided incredible service for 50 years as of the end of this month," he said. "It will provide incredible service in the future."