I agree with lisas9, it really depends on HOW detached the placenta is. If it's complete, I agree with the other ladies, more than likely no, but if it's only partial, it may take a lot of watching over you and baby, but it's definitely more hopeful! Good luck!
The baby wouldn't survive as the placenta is essentially the food source for the baby. If the placenta only partially detaches the baby may have a chance of surviving under the right care.
My friends mom was pregnant and the placenta detached and she got really sick with it. And they had to remove the baby and it died. She was 5 months.
More than likely, no. The placenta is the life line between baby and momma.