LOS ANGELES -- A utility says it has stopped the leak from a ruptured well that gushed massive amounts of natural gas near Los Angeles for 16 weeks.
The leak controlled Thursday drove thousands of residents from their Porter Ranch homes and has been blamed for a variety of symptoms including headaches and nausea.
Southern California Gas Co. tried unsuccessfully for weeks to force mud into the well to stop the leak. It had to drill a second well that intercepted the pipe a mile and a half underground.
The well is not permanently sealed, but if the plug holds it will be cemented closed.
Once state inspectors declare the well permanently sealed, displaced residents will have at least a week to return home.
After suffering from a litany of health problems, Nancy and Larry Davis told CBS News they had to leave Porter Ranch.
"Nosebleeds, nauseous, just couldn't stop coughing," Nancy Davis said.
The gas company has said there will be no long-term health effects, but the Davises don't believe them.
"No," Nancy Davis said. "I have a biochemistry degree, so I don't trust, I don't believe that."
Eight-year-old Nate Soderlund misses his house.
"I've been nauseous. I've felt lethargic," said his mother Christine Soderlund. "My kids have had nosebleeds, they've had headaches."
Two schools have closed because of abnormally high levels of methane, but residents feel they are not getting enough answers about exposure.
"It's surreal," said Christine Soderlund. "We are a living science experiment I believe."
Last month it was reported that the utility for three months knew a devastating blowout was possible because of its age, design and the way it was being operated, according to state records and testimony.
And state regulators were aware of the situation at the largest gas storage field in the West but said they were limited in their ability to stop it.
"There are no rules that prevent it or no law that prevents you from doing what they were doing," said Annaliese Anderle, a former inspector and supervisor at the state Division of Oil, Gas and Geothermal Resources, which regulates the field.
The blowout near Los Angeles has spewed more than two million tons of climate-changing methane and forced thousands of residents to flee their homes amid a sickening stench. Gov. Jerry Brown has declared an emergency and some environmentalists have called it the worst U.S. disaster since the BP oil spill in the Gulf of Mexico.