The shuttering of the trauma unit at the University of Nevada Medical Center, the only Level 1 trauma center in Las Vegas, is a dramatic manifestation of the growing national problem of steeply rising malpractice insurance rates.

The closure was prompted by the mass resignation of dozens of surgeons, who say the soaring cost of malpractice insurance and lawsuits threatened their livelihoods. Emergency rooms around the nation are closing and doctors are withdrawing from high-risk, front-line practice, contending that the costs of lawsuits and insurance are too steep and that local and state governments are not doing enough to protect them.

At University Medical Center in Las Vegas -- the kind of super-emergency room where specialists and surgeons are in the building and ready to operate in minutes -- 11 of 13 general trauma surgeons have resigned from practice, as have all but one of the 58 orthopedic surgeons.

"This is not good," said John Fildes, a surgeon and director of University Medical Center. "We want to be here, that's the sad thing. These physicians want to take care of patients, but they are withdrawing from high-risk activities to protect their families and livelihoods. "

The closure creates a serious potential breach in the region's public health system at a time of heightened security alerts because of possible terrorists attacks during the long holiday weekend.

Attorneys with the Nevada Trial Lawyers Association denounced the closure. "They just wanted to terrorize the community with this walkout," said Jim Crockett, a Las Vegas lawyer. "These doctors are holding this community hostage. "

Crockett and other lawyers say that caps on malpractice awards have not worked in other states that have tried to implement them, and they alleged the doctors were trying to limit their liability in cases of gross malpractice. Furthermore, they said, Nevada is bending over backward to satisfy the surgeons' demands -- first, by offering them raises, and also, by creating a state-backed insurance company to write malpractice policies.

Las Vegas Mayor Oscar Goodman tried to play down the impact, saying the shutdown is "not of crisis magnitude. " He said that patients will still be cared for in emergency rooms, where surgeons are present or on call.

Asked how concerned he is for his residents and visitors in a post-Sept. 11 atmosphere, Goodman said, "It gives pause, but not enough to hesitate. "

Patients who are seriously injured from car wrecks, gunshot wounds, explosions and possible terrorist attacks will be taken by ambulance to local emergency rooms, which will seek to stabilize them and provide care.

But emergency rooms are not routinely staffed by surgeons, who instead are on call and may not be able to attend to cases quickly.

Fildes said that patients in critical condition would likely be transferred by ambulance or helicopter to the closest trauma centers, which are in Salt Lake City, Phoenix and Loma Linda, Calif. The nearest is 188 miles away.

"Trauma patients have one 'golden hour' to get care before their chances of survival decrease precipitously," said Donald J. Palmisano, president-elect of the American Medical Association. "There is simply no substitute for trauma center care for our most severely injured patients. "

The Las Vegas trauma center treats more than 11,000 patients a year from the area, as well as parts of Utah, Arizona and California.

The executive director of the medical center said he would launch a nationwide recruitment effort to bring specialist surgeons to Las Vegas, but he conceded that the trauma center might be closed for six months.

The resigning doctors say they cannot continue to afford to work at the trauma center because medical care they provide there is high-risk, meaning that critical care decisions are made in minutes, often on the operating table.

The surgeons are demanding that the Nevada legislature pass major tort reform, including protection similar to California's Medical Injury Compensation Reform Act (known as MICRA), which places limits on attorney fees and jury awards to patients for pain and suffering.

Fildes and other doctors in Las Vegas contend that local juries often give huge awards to injured patients and that, as a result, medical malpractice insurers have doubled and tripled their rates.

Nevada Gov. Kenny Guinn (R) said he will call a special session of the legislature to address tort reform, but not until July 26, which is the deadline for a negotiating team of insurers, doctors and lawyers that is trying to seek compromise on a reform package.

A number of legislators and public officials have criticized the surgeons for leaving the trauma center without staff.