General Motors is recalling 686,287 crossover SUVs because the pressurized struts that hold up the power rear liftgates could fail unexpectedly. The Detroit maker of Chevrolets and Cadillacs says it’s aware of 56 injuries attributed to the flaw.

“The affected vehicles, equipped with the power liftgate option, have gas struts that hold the power liftgate up when open,” the U.S. National Highway Traffic Safety Administration said in a recall acknowledgment letter dated July 8 that was posted to the agency’s website Friday. “These struts may prematurely wear and the open liftgate may suddenly fall.”

The recalled vehicles are 2008-2012 Buick Enclaves, 2009-2012 Chevrolet Traverses, 2007-2012 GMC Acadias and 2007-2010 Saturn Outlooks.

Later model year vehicles have differently designed struts that are less likely to be damaged by dirt particles that cause the pressurized gas inside the struts to leak, weakening the strength of the power lift of the electronically operated doors.

The recall covers about 690,000 vehicles in the U.S., about 36,000 in Canada and the remainder in Mexico.

Vehicle owners can verify if their cars are affected by plugging their vehicle identification numbers, or VINs, into GM’s recall center website here.