No one on the ground was hurt in the accident midday Sunday at the Sandcastle Resort Hotel, although the car landed upside down on a beach access path yards from a small amusement park. The women had checked into the hotel Saturday.
CBS News Correspondent Jennifer Jones says the New York City women all worked at St. Vincent's Hospital there.
"They're really going to be missed and a lot of the nurses, who knew them better than I, they're really sad today; there are a lot of tears in this hospital," said Dr. Eileen Cassidy.
Police spokesman Don Rimer said there were no signs of skid marks to indicate that the driver tried to stop. Speed and alcohol were not factors, and a preliminary check of the car Sunday found no mechanical defects, Rimer said.
"We've brought in a national expert on this kind of accidenttotal destructionand he's assisting us with the examination of the vehicle," Rimer said Monday, declining to disclose the expert's name. "This is a very slow, methodical process."
Jim Reiner saw the accident. "I heard this car come up the ramp and come around like it was going to park next to me, I turned around to see it time just to see 'em drive through the wall."
It was a cinderblock wall, and a 5-story fall from the top of the hotel parking deck.
Police also were looking into whether the wall conformed to building codes and was substantial enough, Rimer said.
Hotel manager Varshid Vachhani said he was not aware of any problems with the garage. Sandcastle bought the hotel last year but the parking area has been in operation since at least the mid-1980s, he said.
"The management and staff is extremely shocked and saddened by the incident," Vachhani said. "The victims and their families are in our prayers. That's all I could say."
Calls to the city's building inspection department were not immediately returned.
Rimer said the women had driven into the garage just before the accident. The car came up the ramp, turned left and went right through the 3-foot-high wall, Rimer said.
Witnesses, including Doug Saul, said they heard the car's engine revving just before it crashed through the wall. "I saw the front wheels of the car come over, it was still accelerating and then it just done a little topple and come over and landed right on its roof."
The four nurses were still inside. The car was crushed so badly, it had to be taken away to remove the bodies, which were to be taken to the medical examiner's office in Norfolk.
The women had all been on the staff of St. Vincent's hospital for 35 years or more. They were close friends who often went on vacations and to conferences together, said Anthony Gagliardi, the hospital's medical drector.
"These women had dedicated their lives to this institution," Gagliardi said Monday at a news conference at the hospital. "They really had become a family within the St. Vincent's family."
The women, all from New York City, were identified by the hospital as driver Joan Ellen Walsh, 56, case manager for the hospital's pediatrics and neonatal intensive care unit; Mary Ann Going, 60, the unit's nursing care coordinator; Mary Ann Dono, 60, the unit's nurse manager; and Kathleen M. Mollick-Kelly, 63, the head nurse of the pediatrics and obstetrics outpatient clinic.
"It is not an overstatement to note that together and individually, they were the very essence of the mission of St. Vincent's," said Jane Connorton, president of the hospital.
A memorial at the hospital is planned sometime this week.
St. Vincent's, Manhattan, is one of the hospitals run by St. Vincent's Catholic Medical Centers.