by The Associated Press Posted Jun 15, 2015 10:09 am MDT Last Updated Jun 15, 2015 at 1:40 pm MDT AddThis Sharing ButtonsShare to TwitterTwitterShare to FacebookFacebookShare to RedditRedditShare to 電子郵件Email US safety agency investigates complaints of suspension problems with Mazda CX-9 SUV FILE – This April 13, 2006 file photo shows the seven passenger Mazda CX-9 SUV during the 106th New York International Auto Show at the Javits Convention Center in New York. U.S. safety regulators on Monday, June 15, 2015 said they are investigating complaints that suspension parts can come loose on some Mazda CX-9 SUVs from the 2007 and 2008 model years, causing drivers to lose control. (AP Photo/Jason DeCrow) DETROIT – U.S. safety regulators are investigating complaints that suspension parts can come loose on Mazda SUVs, causing drivers to lose control.The probe by the National Highway Traffic Safety Administration covers about 54,000 Mazda CX-9 SUVs from the 2007 and 2008 model years.The agency says it has six complaints that the lower ball joint can separate from the suspension while the SUVs are being driven. No crashes or injuries have been reported. Investigators say the complaints appear to show an increasing trend of problems. Four of the complaints came from states that use salt to clear roads in the winter.Investigations can lead to a recall.A Mazda spokeswoman said Monday that the company will work with NHTSA to support the investigation.