Possible transmission problem

I have a 2013 JKU with an automatic transmission. This morning I was on my way to work and sitting at a red light. All of the sudden I noticed that my tachometer dropped to zero, the engine had just died. 

I put the Jeep in park and turned the key and the engine started right away. I then put it in drive and the Jeep would not move. 

I put it back in park then back into drive and this time the transmission engaged and the Jeep went forward.