A good-morning cell-phone text message. A goodbye peck on the cheek on a subway platform. A dash for a bus and a call to the boss.

As police work to determine the sequence of events in last Thursday's bombings, and Londoners frantically retrace the steps of missing relatives and friends, a countdown to terror has emerged from phone records, witness accounts and indelible memories of loved ones' last moments.

Thursday dawned cool and cloudy as Benedetta Ciaccia stepped onto the 6:25 a.m. train from Norwich, a town northeast of London, to Liverpool Street (search) in the capital's financial district.

Ciaccia, a 30-year-old business analyst, arrived at 8:40 a.m., dressed casually in jeans, a black top and a shark's tooth pendant.

What happened next is unclear: She usually took the Underground to her office, but no one's sure which line she used. What's known is this: From the train, she sent a text message to her Muslim fiancé at 7 a.m., and hasn't been heard from since.

Her fiance, Fiaz Bhatti, fears she caught a Circle Line (search) subway that would have taken her through Aldgate (search), where the first of four bombs exploded at 8:50 a.m.

"I came as fast as I could to look for her, even though I had no idea where to start," he said. "I hope someone will give me some news. If she was in a condition to call me, she would have done so because she knows I'm worried."

Across town at another Tube station, Rob Brennan gave his girlfriend, Elizabeth Daplyn, a goodbye kiss as the two parted company at 8:10 a.m. and headed their separate ways to work.

Daplyn, 26, a manager in the neuro-radiology department of London's University College Hospital (search), boarded the Piccadilly Line to Russell Square, where the worst of the bombings would kill at least 21 commuters.

She never showed up at work, and on Tuesday, her uncle said he doesn't think she made it.

"We're waiting to hear what we already know in our hearts to be fact," the Rev. Tim Daplyn said. "The tense of the language we are using to describe her has changed to 'was' rather than 'is.'"

At the Hendon Central subway station, Anthony Fatayi-Williams, a Nigerian-born oil company executive, phoned his best friend at 8:19 a.m. before boarding.

As he made his way across the city, the bombings began, prompting officials to shut down the Underground system at 9:15 a.m. Fatayi-Williams, 26, surfaced, and witnesses say he was seen helping confused travelers find the right bus. At 9:41 a.m., he called his company, Amec, to say he couldn't get to work on the Tube but would find another way.

His mother and friends believe he hopped on the No. 30 bus that was shredded by a bomb six minutes later, killing 13 passengers.

"I will fight until I die to protect his values and to protect his memory," said his mother, Marie Fatayi-Williams, holding back tears as she struggled with the near-certainty of his death.

Karolina Gluck, 29, bade goodbye to her boyfriend, Richard Deer, as the Poland native boarded the Underground at Finsbury Park at 8:30 a.m.

Her destination: Russell Square. Her fate: unknown. But friends and relatives fear the worst.

"We are really worried. We don't know what's happened to her," said Gluck's twin sister, Magda. "The worst thing is waiting for a phone call."

Moments before Gluck boarded, police say, closed-circuit TV cameras captured all four bombing suspects arriving at the King's Cross subway station. The first bomb exploded at 8:50 a.m. near Aldgate. Among the first on the scene was Olaniyi Falayi, 37, an Underground employee who ran the 100 yards into the tunnel to help the injured.

"It was just carnage everywhere, blood everywhere. It was horrible," he said.

Within seconds, two more bombs exploded — one on a train near Edgeware Road, the other between Russell Square and King's Cross stations. By 9:15 a.m., the entire Underground ground to a halt as officials shut down the system.

Commuters dashed for buses, many unaware that terrorists had struck and the city was under siege. Unable to get a subway at the King's Cross or Euston stations, Lisa French phoned her husband to say there was some kind of problem but that she was safe.

A few minutes later, she boarded the No. 30 bus, taking a seat on the top deck. At 9:47 a.m., a bomb ripped through the bus, sending metal, glass and body parts raining down on Tavistock Square.

Philip Russell, 28, called his bosses at JP Morgan to say he was evacuated from the Tube and was taking the bus. He ended up among the 13 who were killed.

"He's a wonderful kid who was in the wrong place at the wrong time," said his father, Grahame.

French, amazingly, escaped with scratches.

"As I looked up and looked around the roof of the bus had gone and you could feel things coming over the back of your head, dust and smoke," she said in an interview with Britain's ITV television. "All of the seats behind us had gone and everything was gone. It just wasn't there any more."

"It was very eerie and very surreal and just bewildering," she said.

A series of rapid-fire announcements followed as the gravity of the situation becomes clear. They culminated at noon with an address to the nation by Prime Minister Tony Blair, who confirmed deaths and serious injuries in a series of "barbaric" terrorist attacks.

The chain of events ended with this jarring footnote: At 10 p.m., the family of one of the suspects reported him missing, police said Tuesday. They said some of his property was found on the bus.