Copiapo, Chile (CNN) -- A bore hole reached 33 trapped Chilean miners Friday, officials said, but it must be widened before the miners can squeeze through -- a process that should take a few weeks.
The "Plan B" drill was welcomed by the jubilant workers as it reached its target in the mine's workshop, 623 meters (about 2,040 feet) down, at about 10:30 a.m. ET Friday, officials said.
"Once we got back to drilling it went very good, the rock was real tough the last few hours, but we did it," said Brandon Fisher of Center Rock Inc.
Miners assisted the operation by offering guidance for the drilling. The workers could be rescued, if all goes well, in late October or early November.
Officials already are planning how they will bring the miners to the surface once a bore hole is wide enough for the task. The daunting rescue may require an oxygen-fed cage that will haul them up one at a time. The trip, which was first thought to require two hours, may be doable in 15 minutes, officials said.
Friday's development was bright news indeed for the miners, who will enjoy a feast and celebrate Chilean independence day Saturday.
Plan B is one of three options for reaching the group.
Drilling under Plan A will stop this weekend once the drill bit reaches 380 meters (about 1,250 feet). The drill will receive scheduled maintenance before resuming early next week, engineer Rene Aguilar said. Engineers estimated that this plan would take between three and four months to complete the hole.
The assembly of the drill to be used in Plan C has been completed, an official said, adding that he hopes it will begin drilling this weekend.
Meanwhile, a senator representing the region said better government regulation could have prevented the situation.
"This accident could have been avoided and we could have avoided seeing the anguish of 33 families waiting for their loved ones to come home," said Sen. Isabel Allende, who represents the Atacama region where the San Jose mine is located. "This could have been avoided if we had businessmen with a sense of social responsibility. You cannot carry out a mining operation at the cost of miners' lives."
Allende -- the daughter of former Chilean President Salvador Allende -- said government regulators, who temporarily closed the mine in 2008, should have been more vigilant.
"State organizations did not fulfill their role. Instead of shutting down this mine for seven months, they should have closed it for good," she said.
Two lawsuits filed last month alleged that the San Esteban Mining Co., which owns the mine, violated laws in failing to provide sufficient security.
The mine reopened in 2008 after a yearlong closure without the proper safety measures being put in place, including measures to shore up the rock face, according to attorney Remberto Valdes, who is representing one of the miner's families.
"It has been proven, the mine did not have a second escape route and there was no ladder in the ventilation chimney," Allende said Thursday.
At the time when the suits were filed, there was no response from the mining company.
But shortly after the mine's August 5 collapse, company manager Pedro Simunovic said there was no way to know it would happen.
"This was impossible to predict," he said, according to CNN Chile.
Asked whether new laws are needed to enforce mining codes, Chilean Mining Minister Laurence Golborne told CNN that mining laws are not to blame for the men's predicament.
"The problem was that the owners did not do what they were told to," he said. "Not because it was too expensive or they were greedy, but just because they didn't care. ... We have got good regulations but maybe we need to improve auditing of those regulations."
Representatives of the San Esteban Mining Co. have said previously they will collaborate fully with Chilean authorities and the Chilean Congress in their inquiries about what went wrong at the mine.
The miners' plight quickly caught the attention of officials and politicians.
When the 33 first sent word that they were alive, President Sebastian Pinera triumphantly waved their written note before the media.
Even though her Socialist Party opposes Pinera's government, Allende praised his handling of the situation Thursday.
"This accident has increased the popularity of President Sebastian Pinera. It is something he has earned because he took decisive action to save the miners, and that has meant he has risen in the opinion polls," she said.
Allende's father, who died in Gen. Augusto Pinochet's 1973 military coup, completed the process of nationalizing the Chilean copper industry in 1971. Average Chilean copper prices this year are near historic highs.
But even so, Allende said her father would have viewed the current situation with "great sadness."
"He would see that even when the price of copper is high, that does not translate into better salaries, better working conditions or better safety," she said. "Businessmen have no greater social conscience and are no less voracious than before."
Earlier Thursday, Golborne expressed optimism that the 33 miners will be rescued in early November and maybe sooner.
"Everything is going a little bit better than anticipated," Golborne told CNN about the Plan A, Plan B and Plan C holes being dug in an effort to open a passageway to safety for the men.
Two bore holes -- each about 8 centimeters in diameter -- are currently being used to supply the miners.
The first carries compressed air, water, communications and a constant supply of electricity to power lights that are used to simulate daytime and nighttime.
Supplies -- such as food, clothing and letters -- are sent down to the miners via metal cylinders known as "carrier pigeons" through the second bore hole.
CNN's Patrick Oppmann and Esprit Smith contributed to this story.