INSTITUTE, W.Va. - Local residents say an emergency notification system failed its first major test at a Union Carbide Corp. plant after a choking cloud of gas rolled over four cities, injuring 136 people.

Six plant employees, one seriously injured, and about 130 nearby residents went to hospitals Sunday with lung, eye, nose and throat irritations after a chemical used to make pesticide leaked. Thousands of people were asked to stay in their houses for several hours, until the chemical dissipated.

Union Carbide officials said the unit was shut down following the leak, but that workers were on the job today in other parts of the plant. Meanwhile, the company planned to respond formally to complaints about its emergency notification procedure but had not decided on a format, said spokesman Charles Ryan.

The chemical cloud spewed from a unit that uses methyl isocyanate, the substance that leaked last December in the Indian city of Bhopal , killing more than 2,000 people. Plant spokesman Dick Henderson said the substance that leaked here, aldicarb oxime, is made from MIC, but the MIC is consumed in production.

Company officials said a cloud of aldicarb settled on nearby homes after leaking from the plant when a gasket on a storage tank failed.

Many people living near the plant said their homes already were engulfed in fumes when they first heard the plant's emergency siren. "Carbide's got to do something better than this," said Donna Willis, one of nearly 300 residents examined at an emergency clinic.

"We can't let them wait 10, 20 or 30 minutes before they let you know what's going on. We could have been dead," she said.

The company said it notified the county Office of Emergency Services of the incident within "approximately five minutes" of the leak.

Henderson said the Carbide plant sounded a warning siren as soon as the leak was detected.

But emergency personnel in Charleston, about 12 miles away, were not told, according to Mayor Mike Roark.

"Each municipality is supposed to be notified," he said. "Our command center was not notified. Our public safety director heard it on the (police) scanner."

"They did not notify anybody other than making an initial call to the county," Roark said, "and the information that came from them was sparse to say the least."

"If it had been something really bad, it would have been too late," said Vicky Terry, who said she awoke to find her home full of the stinging fumes. "People would have been dead in their beds," she said.

Reports of noxious fumes began spilling into radio stations about 9:45 a.m. 8:45 a.m. Houston time), said WCHS news director Mike Wilson. He said public notification was hampered because most radio and TV stations don't staff their news departments on Sunday mornings.

"Sunday morning is a very inconvenient time to have something like this," he said.

Emergency broadcasts beginning about 25 minutes later asked Institute's 3 ,100 residents to remain indoors, close windows and shut off air conditioners. An all-clear was broadcast shortly before noon.

Barbara Cyrus, who