FIREFIGHTERS were getting several hoax calls from the same phone box in Kirklees.
So they out-thought the troublemakers and caught them red-handed.
The hoaxers were using the same phone box in Cleckheaton to make the malicious calls.
As soon as the next call was made, the station officer drove straight there in a car while the fire engine went on the call - and he nabbed the callers.
They were handed over to the police and prosecuted.
All fire engines have CCTV cameras, which can film the hoaxers - or arsonists - who hang about at the scene. The film can then be used in court.
The West Yorkshire fire service responds to around 2,500 hoax calls a year. It is working with schools and in the community to try to reduce that figure to 1,571 by 2013.
Thousands of other hoax calls are weeded out before fire engines are turn out.
Experienced call centre operators at service headquarters in Birkenshaw now challenge people they suspect of making a malicious call.
And since that policy was introduced several years ago, the number of hoax calls has fallen.
Senior Fire Safety Officer Nigel Charlston said: "Over the last 12 months we received 6,000 malicious calls and sent fire engines out to 2,500 of them."
Principal Fire Control Officer John Naylor said: "If we suspect we are talking to a malicious caller, we warn the person the phone call is being recorded and if it is malicious we will look to prosecute.
"We then ask them if they want to continue with the call. Many don't."
A lot of the hoaxers are children claiming all kinds of incidents have happened, from rubbish fires to house blazes and car pile-ups.
But not all hoaxers use the phone.
Some smash automatic fire alarm glass in buildings.
Their motives vary. Some send fire engines to their workplace if they've fallen out with the boss or been sacked.
Schoolchildren smash automatic fire alarms, so the school is evacuated and they skip the lessons they hate.
Others do it just for the sheer thrill.
Mr Charlston said: "Some people simply like to see a big red fire engine with blue flashing lights. I don't know why."
And he added: "Every time we send a fire engine to a hoax call we are putting both the crew and members of the public in potential danger.
"We are rushing to get to a fire which has never happened under blue light conditions.
"And, of course, while we are tied up on a malicious call, a genuine emergency may come in. A fire appliance then has to be sent from another area, which could lead to a delayed response."
The fire service has an agreement with phone companies and phones - both mobile and landline - can be quickly disconnected if a hoax call is made from them.
The West Yorkshire fire service receives 98,000 emergency calls each year.
Its target is to take the message from the caller and get the information to the fire station within a minute.
The average is 56 seconds - but obviously hoaxes can delay this.
Apart from the hoax calls, firefighters also get inappropriate ones - including the old cliche of cats stuck up trees.
But fire crews no longer go to these jobs.
Mr Naylor said: "We ask them to call the RSPCA and if they assess the situation and need help, we will then provide it."
Other people wrongly dial 999 to try to get firefighters to deal with burst pipes or floods.
They are advised to phone a plumber.
But frontline firefighters do give free home safety checks.
And they put up free smoke detectors in the homes of elderly and vulnerable people.
People can organise a free check by phoning 0800 587 4536 or contacting their local fire station.
The main numbers are:
Huddersfield 01484 532223
Slaithwaite 01484 842618
Brighouse 01484 714992
Elland 01422 372862
Dewsbury 01924 465601
* Of the 30m 999 calls handled by BT, a staggering 52% were hoax, misdialled or not appropriate for the emergency services
* Fire brigades bore the brunt of hoax calls, with 67,100 found to be malicious last year
* The malicious calls made to fire and rescue services cost an estimated £24m last year
* Hoax calling can carry a maximum penalty of up to three months in prison
* Police say 999 calls should only be made to them if life is at risk or a crime is actually happening there and then
* Hoax and inappropriate calls - such as people calling an ambulance if they are suffering from toothache - are also a big problem in West Yorkshire
* The number of hoax fire calls has fallen in recent years, but 2,321 were still made over the last year.