Passengers at Heathrow bound for Kenya are shocked that all UK flights in and out of the country have been grounded but even an "imminent threat" of terrorist attacks on British plans is not going to stop some travellers finding alternative routes.
On the departure board flight BA065 is flashing as being cancelled.
That a security alert is the reason for the grounding comes as a surprise even to the British Airways check-in staff.
Flight BA065 was going nowhere on Thursday night
"Yes, the flight is being cancelled," says one looking at his computer screen.
Do they realise that there is an "imminent threat" against UK airlines bound for the African country due to a threat possibly posed by al-Qaeda?
"Oh my God," he exclaims.
The total halting of all Nairobi-bound UK flights is equally shocking to Kenyan Naheeda Karmali.
"How do they figure out there is going to be an attack," she says, freshly arrived from Vancouver in Canada and desperate to be back with her family in Africa.
"It's scary as Nairobi Airport is such an easy target.
"It seems that the Kenyans are being dragged into the war on terrorism and we haven't done anything," she continues.
She is quickly on the phone to her relations.
"Mum? Yes I know," she says down the phone.
Ms Karmali's mother is an airline employee and has already worked out an alternative route avoiding British carriers.
"She says it is only UK planes that will be targeted," says Ms Karmali.
Other passengers are adamant they will reach their intended destinations, despite the alert.
Gregg Fasse and his family were among the 56 travellers who had already checked in when BA065 was cancelled.
"The information we were given in the departure lounge was very vague but we are still going.
"We are going to teach at a school there for five years," he said.
His wife Cheryl says she, her husband and their three children have always felt very safe in Kenya and intend to fly there at once via South Africa.
"If it was really unsafe our school would have told us not to come.
"I am more worried about losing our 28 bags. Our whole life is in them."
Anthony Pariola is frantically running between the BA desk and the parking bay where his elderly mother Margaret Newland sits in his car anxiously awaiting information about her prospects of attending a family funeral in Nairobi.
Hearing of the South African route, Mrs Newland is gleeful.
"So we can go?," she asks, "I am so happy. I have a funeral to attend. It's for my niece."
Her son quietly confides he would prefer his mother to stay at home.
"I put myself in the hands of the pilot," she insists.
"The pilot knows whether it is safe.
"If there is a route open I will take it. If there is a real danger they will ground all planes."
American students Dustin Haselton and his friends are prepared for camping the night on the airport floor waiting to find a way to reach Nairobi.
But Mr Haselton is determined the terrorists will not prevent his party from going to work at a Kenyan home for children orphaned by Aids.
However the students fear that as American passport holders they will be particular targets for terrorist attacks.
"We thought about wearing t-shirts with Canadian flags on them," Mr Haselton jokes.
But beneath the good humour the students are concerned for their families back home in Vermont.
"I just talked to my mom," says Christi Hubbard, "She'd like me to go home but we have been planning this for a year so we will go on."
But this optimism is quickly crushed when their tutor returns from contacting Vermont.
The trip is off, thanks to a Washington advisory that no American should venture to Kenya.
"It is just so sad," says Miss Hubbard as other students wipe tears from their eyes.
"The trip was such a good way for us to see the problems in Kenya and try to do something about them.
"But there is nothing we can do. I have faith I will get there some day," she says.