Hello Doc, My Wife Experienced Severe Pain And There Was

Hello Doc, My wife experienced severe pain and there was no fetal movement in her womb in her 29nd week of pregnancy. I immediately rushed her to the hospital. The doctor administered some pain relief medicine and injection, they admitted her but didn't carry out any ultrasound. The following day pain was reduced but there was still no fetal movement but heartbeat was normal. Doc said if heartbeat is there baby is fine, fetal movement is not important. The next day they didn't find any heartbeat and ultrasound carried out which confirmed a dead foetus and liquor volume was grossly reduced.
We carried out ultrasound in may 16 where everything was perfectly ok. Now what could have gone wrong. The doctor is not able to give any satisfactory answer, there was no placenta abruption, no blood clotting no infection. So what is the reason. How liquor volume reduced grossly? All this questions killing me. I lost my 1st baby last Sunday, my wife is devastated and crying inconsolably.
Any help will be greatly appreciated.