WASHINGTON — At first, the only remarkable thing about Sept. 11, 2001, was the weather — a chill hint of fall under a brilliant blue sky.
“I remember walking to the office and it was a beautiful day,” said former Lowell representative Martin Meehan. As usual, he headed in from his Capitol Hill apartment a little before 7:30 a.m.
About an hour later, Worcester Representative Jim McGovern began his own walk to work from his home, stopping to drop off his son at a day-care center near the Capitol building. Ed Markey, then a Malden representative, was driving in from the Maryland suburbs.
On the other side of the Capitol complex, Edward M. Kennedy was waiting to greet first lady Laura Bush before she appeared at an education hearing he was chairing. The other senator from Massachusetts, John Kerry, was heading to the Capitol for a meeting.
Shortly before 9 a.m., they and the rest of the nation began hearing bizarre reports: a plane had slammed into the North Tower of the World Trade Center in New York City.
Within the hour, after the other tower was hit and the Pentagon was struck, it became as clear as that cloudless sky that the nation was under terrorist attack. Chaos broke out in Washington as fears spread that the Capitol building or the White House would be next.
For Massachusetts lawmakers and their staffs, the crisis was amplified. Two of the hijacked airliners departed from Boston, filled with local passengers and flight crew. Desperate for information, relatives and friends began frantically calling their representatives.
Before Sept. 11, partisan divisions ran deep. It was just nine months since a controversial Supreme Court ruling decided one of the closest presidential elections ever and many Democrats remained bitter.
But as the sun set on Washington that day, another remarkable thing happened: Democrats and Republicans put aside their differences to come together in arguably the country’s last instance of true unity.
“There was a shared grief,” Markey recalled, “which is a sad form of unity but binding nonetheless.”
Kerry can still remember the sound.
At the weekly meeting of Senate Democratic leaders, on the second floor of the Capitol, everyone was glued to the TV. A second plane had hit the South Tower, and the World Trade Center was smoldering.
“Suddenly there was this huge clap, explosion, and we ran to the window . . . and this massive cloud of black smoke was rising from the Pentagon,” Kerry recalled. “Everybody knew we had to evacuate the building.”
Washington now was also under attack.
A 2002 BBC documentary showed video of the scene outside the Senate just before 10 a.m., with Kerry looking skyward as he and others hustled down the Capitol’s steps. “Ladies and gentlemen, let’s keep moving away from the building,” a police officer instructed through a bullhorn.
Laura Bush’s hearing was postponed and she hunkered down with Kennedy in his personal office in the Russell Senate Office Building while her Secret Service detail figured out what to do. The two were joined by then-New Hampshire senator Judd Gregg, the committee’s top Republican, and Kennedy’s Portuguese water dog, Splash.
“It was almost surreal,” Gregg remembered. “We’re sitting there on the couch, and Ted started going around his office, pointing to pictures of his family, mostly [President John F. Kennedy], and relating stories about the crises that they had.”
Laura Bush thought that might have been Kennedy’s way of coping, after the assassinations of his brothers and other family traumas.
“I have often wondered if the small talk that morning was Ted Kennedy’s defense mechanism,” she wrote in her memoir. “If . . . he simply could not look upon another grievous tragedy.”
The rapidly unfolding events overwhelmed the cellular networks. Even President George W. Bush, flying on Air Force One after cutting short an event in Florida, had trouble getting through to his wife.
Kerry hurried back to the Russell building, where he ran into Delaware Senator Joe Biden.
“There’s another plane on its way to Washington,” Kerry recalled Biden telling him. “We think it’s heading towards the Capitol and we need to get everybody out.”
Kerry rushed to his office and scoured the suite to make sure all his staffers had left.
“I remember feeling just this incredible, huge sense of anger and sorrow,” Kerry said. “I wanted to grab a weapon. I wanted to do something in response.”
In the Cannon House Office Building, McGovern was watching reports of the Pentagon crash when he heard a commotion.
“I just remember Capitol Police running through the hallways saying, ‘Everybody needs to evacuate! Everybody needs to evacuate!’ ” he said. “I was like, ‘What the hell is happening here?’”
Springfield Representative Richard Neal, who had flown into Baltimore from Hartford that morning, arrived on Capitol Hill to find thousands of people on the streets. Confusion was spreading.
“Nobody was quite sure where Air Force One was. . . . Nobody knew where the vice president was,” Neal recalled. “There was the story that the plane had gone down in Pennsylvania, and the rumor started that the plane actually had been headed to the Capitol dome.”
Rumors ran rampant: a bomb at the State Department, a fire on the National Mall. The White House and federal buildings also had been evacuated. And people still feared the Capitol building was in danger.
Markey was behind the wheel of his Buick Skylark on Capitol Hill, making calls on his flip phone whenever he could get a signal.
“My first thought was just to protect my staff and ensure that they were safe, and then try to ascertain what was going on,” he said. “There was an information vacuum.”
The first hint that Meehan had about the impact of the terrorist attacks in Massachusetts came in a call from economist Martin Fleming, a friend he had grown up with in Lowell. Fleming feared his brother-in-law, Patrick Quigley IV, of Wellesley, was on one of the planes and asked Meehan to try to find out.
“That’s when I realized that at least one of these flights left from Boston,” Meehan said. He later learned Quigley had died.
In Meehan’s Lowell district office, the phones began ringing.
“We lost more than 30 people from the Merrimack Valley, and they weren’t strangers to us. They were our neighbors,” recalled Lori Trahan, a Meehan staffer at the time who now represents Lowell in the House.
“My own neighbor . . . lost her husband,” Trahan said. “I was one of the people in the district office who local families were calling in the worst moment of their lives, trying to get more information.”
The staff members in Lowell soon lost touch with Meehan’s D.C. office as the Capitol complex emptied.
“It was eerie, and it was scary,” Meehan said of the crowded streets on Capitol Hill. “People were saying, ‘There’s another plane out there. There’s another plane out there.’ We were anticipating that there was going to be another attack somewhere. I was thinking the Capitol or the White House.”
Meehan found some of his staffers and they headed to his apartment, which had a landline. McGovern made the same decision with his staff as he heard sonic booms from fighter jets echo across the sky. He was worried about his 3-year-old son, Patrick, at day care, but he couldn’t reach his wife at home with their infant daughter, Molly.
McGovern, with his staff in tow, headed to the Little Scholars day-care center. As they approached, they ran into Lisa Murray McGovern also rushing to the center, carrying Molly in her arms.
“His day-care center was only like six blocks from the Capitol, and I was like, ‘I just need to get him.’ And she thought the same thing,” McGovern said. “Some of the people at the day-care center didn’t know what to do, where to go. So we told them, ‘Come back to our house.’ ”
The day-care workers camped on the first floor of McGovern’s Capitol Hill home while he and his staffers worked on the second, trying in vain to get information.
It was the same scramble for Markey, who represented the area around Logan Airport.
In his district, seven people from one employer alone — TJX Companies in Framingham — were on American Airlines Flight 11. They were among the 206 people with Massachusetts ties who died in the attacks.
“The flight attendants and the pilots lived in Winthrop, lived in other communities that were near the airport,” he said. “We were trying hard to get information, but official sources themselves were were not able to respond.”
At the Senate Russell Office Building, Laura Bush was now sheltered in Gregg’s office. After both towers collapsed, the Secret Service was prepared to move her to a secure location.
“They took her out,” Gregg said, “and then I literally was the last person in the Russell office building.”
Gregg got in his car and drove home to suburban Virginia, passing the burning Pentagon on the way.
One of the rumors spreading all day on Sept. 11 turned out to be true — the Capitol building was a target.
After taking off from Newark for San Francisco, United Airlines Flight 93 made a U-turn over Ohio. The terrorists planned to fly the plane into the White House, with the easier-to-spot Capitol building the alternate objective, according to the 9/11 Commission Report.
Instead, passengers courageously rushed the cockpit and tried to seize control from the hijackers. The airliner crashed in a field in Shanksville, Pa., at 10:03 a.m..
“We are sure that the nation owes a debt to the passengers of United 93,” wrote the authors of the 9/11 report. “Their actions saved the lives of countless others, and may have saved either the Capitol or the White House from destruction.”
Congressional leaders had been rushed to secure locations and all air traffic in the country was grounded. By late afternoon, confident the nation’s capital finally was safe, President Bush headed back to Washington to address the nation.
House Speaker Dennis Hastert and Senate majority leader Tom Daschle — a Republican and a Democrat — also returned and decided to make brief statements outside the Capitol building at 7:15 p.m. with as many lawmakers as they could assemble.
Senators and representatives were scattered around the Washington area. Markey was driving home when he got the call and turned around because he thought it was important to be there. Meehan also raced over from his apartment.
“Democrats and Republicans will stand shoulder-to-shoulder to fight this evil that’s been perpetrated on this nation,” Hastert declared at the foot of the Capitol’s East Front steps. “We will stand together to make sure that those who have brought forth this evil deed will pay the price.”
After he and Daschle finished their remarks, there was a moment of silence. Then, as some of the dozens of gathered lawmakers began filtering away, someone began singing “God Bless America.”
“I don’t remember who started it, but by the end of it, everyone was in it,” Meehan remembered. “It was an instance of complete unity.”
The moment, broadcast around the country, provided a hopeful coda to a day that took nearly 3,000 lives and shattered countless others. The bipartisan resolve forged on 9/11 extended for months as the nation began the war on terror.
“President Kennedy’s funeral would probably be the last thing I can think of where the nation came together with as much emotion,” Kerry said.
Bush drew praise from Democrats for his leadership in the immediate aftermath of the attacks. There was no partisan finger-pointing: Democrats didn’t blame Bush, and he didn’t blame his predecessor, Democrat Bill Clinton. Conspiracy theories quickly flared up — 9/11 gave birth to the word “truther”— but took a while to spread without the accelerant of social media.
The bipartisan unity began cracking in early 2002 when Bush turned his attention from Afghanistan — where the Al Qaeda terrorist network behind the attacks was based — to Iraq. The resulting Iraq war ultimately split the nation.
It’s been bitterly divided ever since.
That division fuels concerns among Massachusetts Democrats about whether Washington could summon that unity now, 25 years later, if facing a similar threat.
“I think it would be very hard, where now social media amplifies any conflict, to find any sort of broad agreement,” Neal said. “When I hear some of the arguments about the conspiracies now from the House floor and the things that people say, it’s pretty wild.”
Those lawmakers also question whether President Trump could rise to the occasion as Bush did.
“I don’t say a lot of nice things about George W. Bush, but I thought he understood the importance of holding this nation together,” McGovern said. “I don’t know if that kind of leadership exists right now.”
Gregg, a Republican who left office in 2011, acknowledges the deep partisan divisions these days. But he believes reaction to seismic events will always transcend those differences.
“For something that involves an attack on our nation or our our way of life,” he said, “I’m absolutely sure that the country would pull together.”
Jim Puzzanghera can be reached at jim.puzzanghera@globe.com. Follow him @JimPuzzanghera.