I was written up for an incident at work that happened 2 weeks ago but now 3 days later they said there opening an investigation and have currently suspended me from work and say I may possibly be terminated at work. Is this wrongful since I have already

I work at a retread plant and we are not allowed to turn off the computer that scans the product, only the supervisor can. The computer kept going off for false readings , which happens alot, but this day it was going off alot more frequently than usual so after about the 20th time I reset the computer myself instead of calling the supervisor back over. 2 weeks later my supervisor writes me up for it and has me sign it and said it's for that incident. Well now 3 days after I was wrote up they called me before my shift started and said they are gonna open up an investigation on me and suspend me till it's over and that I may be terminated. Can they do that since I was already written up for that same incident?