As far as the wife-- typically news of a patient's death is not given over the phone. We usually say something like, "My name is Jordyn and I'm the nurse taking care of Johnny. He was involved in a car accident and is critically ill and we need you to come to the hospital. Please take your time and drive safely and we'll talk more when you get here."
When the spouse arrives they are usually taken to a small family room where the attending physician and likely the nurse (or some other person who can care for the spouse so the physician can leave) delivers the bad news. We don't use phrases like passed on, gone home, or lost the battle. It usually goes something like-- "Johnny was involved in a serious car accident. Despite our best efforts your husband died from his injuries."
The first part should be short and to the point because families don't hear much after you tell them that their loved one has died. Then we'll usually take the family's lead and let them ask whatever questions they need to.
Usually there is some prepping of the body so it's as presentable as possible. However, if the patient is going to be a coroner's case then all lines and tubes must be left in place. This is explained to the family as well as to what they'll see when they get into the room.
"I'm going to take you to see Johnny now. Just so you're aware he has a tube still left in his mouth and nose and several IV's in place. His face is very bruised from the car accident and his left arm is deformed from a broken bone."
Something along those lines. Even if the patient hasn't died-- we do try and prep the family for what they will see.
Families are given as much time as they want to be with the patient. If the ED is CRAZY busy and we absolutely need the room, arrangements might be made for the patient to go to a med/surg room to give the family more time with the body. It would mean needing to move the patient out of the ER for this and would be very rare.