opel Zafira wheel nuts coming loose

[donee]

recently my wife's car was missing a wheel nut and two others were loose. we only noticed as it was causing a slight noise but today she and the kids were on their way to Ballyer and the same knocking sound was there, but now two wheel nuts are missing and all the wheel nuts were loose when she arrived . is this normal
i havent offended anyone that i now of.
the street where we live isnt greatly lit
should we inform the Gardai
thanks in advance.............

 

[fraggle]

are they the correct wheel nuts? do you have the car from new?