Look out below...

The blades and a rotor fell off of a wind turbine in North Dakota on March 14, according to this Business Week report. Inspectors say malfunctioning bolts were the problem.

And on Feb. 8 a lighting fixture fell from the ceiling in the heavily traveled Central Artery Tunnel in Boston's Big Dig project. No one was injured by the lighting fixture, but the incident brought back sad memories of the motorist who was killed in 2006 in one of Boston's new Big Dig tunnels when several 4,600-pound concrete panels fell from the ceiling, crushing her car.

No one is certain yet why the 8-foot long, 110-pound lighting fixture fell, but the early speculation is that one or more of the brackets attaching the fixture to the tunnel wall got corroded by salt air, moisture and de-icing solutions. NuArt Lighting, Fullerton, Calif., is the manufacturer of the fixture. A March 16 report at www.boston.com said 95% of the 23,000 lighting fixtures in the Big Dug tunnels inspected by that time were safe. All fixtures will be inspected.