The first plane hit the north tower at 8:46 a.m.
About 17 minutes later, the second plane smashed into the south tower, sending fireballs shooting into the sky.
Another airliner punched into the Pentagon. A fourth went down in rural Pennsylvania.
Tens of thousands of people witnessed the destruction firsthand.
Hundreds of millions more watched the terrible events unfold on television screens around the world.
Sept. 11, 2001, the bloodiest terrorist attack on U.S. soil, fundamentally changed the American experience.
Thanks to secluded geography and a host of political reasons, the United States in recent memory had largely enjoyed a level of security and safety unknown to most other parts of the world.
Although it's been more than eight years since the attacks -- and New York City is a long way from Sandusky -- we felt the reverberations of Sept. 11 here and continue to see them today.
Sandusky is a different place today than it was Sept. 10, 2001.
Security increased for travel
Judy Hippler, 67, Castalia, was supposed to pick up her cousins from the Detroit airport at about 1 p.m. Sept. 11, 2001.
Her cousins, who were in their 70s, were visiting from Luxembourg, but their plane was redirected to Toronto because of the attacks.
After their plane landed at the airport in Canada, officials rifled through her cousins' luggage and interrogated them for hours.
Eventually, officials determined the cousins and other passengers posed no threat and allowed them to enter the country.
They arrived at the Detroit airport about 4 a.m. Sept. 12.
Hippler said she apologized to her cousins for the ordeal, but the cousins insisted no apology was necessary.
"We have not been through anything -- your country is the one who has been suffering," they said.
Air travel has not been the same since Sept. 11.
Travelers used to board planes with lighters, scissors and other potentially dangerous items. Not anymore.
Travelers are required to remove their shoes, transfer shampoo and other liquids into clear plastic bags and are subject to searches.
Security measures at airports are tenfold what they used to be.
People used to go to airport gates without a ticket and say goodbye to relatives and friends as they boarded the planes.
Travelers' tickets and identification cards are now checked several times before they're allowed access to the terminals.
A passport is now required to visit our neighbors to the north and south.
Following Sept. 11, the U.S. Department of Homeland Security created a color-coded system to notify Americans of the likelihood of another terrorist attack.
The five-color system is supposed to tell Americans how on guard they should be for another incident of violence.
The effectiveness of the system has been widely criticized, because the threat levels are vague.
According to Homeland Security's Web site, the threat level never dropped below yellow from March 2002 to August 2006.
Yellow signifies the threat is elevated, meaning there's a significant risk of terrorist attacks. At times during those four years, the threat level was orange, signifying the threat is high.
Only once was the threat raised to red, signifying a severe risk of attack.
Authorities in Ottawa and Erie counties in early 2008 pointed out that the counties are separated from Canada only by Lake Erie, meaning illegal immigrants could sneak in undetected by boat.
Hoping to better secure the border, U.S. Border Patrol opened an office in downtown Sandusky. They have a strong presence in the downtown area and agents patrolling in trucks can be found as far south as Huron County.
Officials have beefed up border security in the wake of Sept. 11.
In June 2008, members of the 200th RED HORSE Squadron at Camp Perry visited Arizona to help the Border Patrol build roads and run electrical lines to better protect against illegal immigration and drug trafficking.
"They have cameras everywhere (on the border)," said Col. Michael Skomrock. "(Border Patrol agents) see somebody come over, they respond to it in their jeeps. They had trails they used to travel on, and they could go 15-20 mph. (With the new roads) they can go about 50 mph now."
After Sept. 11, the federal government began cracking down on illegal immigration like never before.
U.S. Immigration and Naturalization Service was dissolved in 2003 and three agencies were created to handle its responsibilities.
Most notably was the agency called U.S. Immigration and Customs Enforcement.
According to the agency's Web site, ICE was created in response to the terrorist attacks and is charged with protecting "the security of the American people and homeland by vigilantly enforcing the nation's immigration and customs laws."
ICE was responsible for the arrest of 58 employees at eight Casa Fiesta restaurants in northern Ohio. The agency made 4,900 arrests in work-site enforcement cases in 2007.
Critics claim ICE and Border Patrol often violate Hispanic residents' constitutional rights by racially profiling them.
A class-action lawsuit filed earlier this month in U.S. District Court in Toledo alleges Border Patrol agents interrogated, detained and arrested people based on their Hispanic appearance rather than probable cause.
Signed into law in October 2001 by President George W. Bush, the USA Patriot Act gave greater surveillance power to law enforcement agencies.
Federal authorities cited the act when the public learned the government was conducting secret, intelligence-gathering searches. The government was eavesdropping on phone conversations, monitoring e-mails and searching personal records without obtaining court warrants through the standard process.
It also allowed authorities to search things once off-limits, like library records.
Critics said many of the act's provisions were unconstitutional and violated the rights of U.S. residents to privacy.
Some of the court challenges led to revisions in the legislation.
In the aftermath of the attacks, the U.S deployed troops first to Afghanistan and then Iraq.
Many local residents who enlisted in the military were sent off to distant and dangerous lands.
Many soldiers had close calls but managed to complete their military tours without suffering injuries or loss.
Some returned home and then later shipped out for their second or third tour.
Some didn't make it home at all.
The list of fallen soldiers includes locals Sgt. Benjamin Biskie, Spc. Charles Odums II, Pvt. Jason Sparks, Sgt. Michael W. Finke Jr., Lance Cpl. Jeremy Shock, Sgt. Keith Kline and Staff Sgt. Jon Martin.
Loved ones say the pain of their loss has not weakened in the days, months and years since the soldiers' deaths.