Chelsea's players had to be evacuated from their Cobham training ground due to fears of a chlorine leak.
The Sun reports that the incident took place on Friday, when the Blues' first-team squad and staff had to leave the complex's main building after a fire alarm went off in the swimming pool area.
Enzo Maresca was able to get out on the pitch and deliver his final tactics ahead of Chelsea's Saturday clash with Sunderland
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Enzo Maresca was able to get out on the pitch and deliver his final tactics ahead of Chelsea's Saturday clash with SunderlandCredit: Getty
Surrey Fire and Rescue service personnel were quickly on hand, rushing to the scene in the afternoon to investigate.
It is understood that Chelsea's players were already decked out in their training kit when the incident took place.
Fortunately for Enzo Maresca's side, their preparations ahead of their Saturday afternoon clash with Sunderland weren't affected.
They were able to go out onto the training pitch and complete their 3pm session ahead of today's Premier League fixture.
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And after the fire staff confirmed it was a false alarm, players and staff were allowed to return to the building to collect their belongings.
What have Chelsea said about the incident?
Chelsea revealed in a statement: “Fire services responded to an automatically triggered alarm at Chelsea FC’s Cobham training faciliity.
“As a precaution, all staff were safely evacuated.
“Emergency services confirmed a false alarm, and staff and players were able to return to the building.”
The Blues will certainly be relieved no fault was found with their 56ft hydrotherapy pool.
It is a key part of their state-of-the-art Cobham facility, which cost the club £20million to open in 2007.
The Blues stars were all smiles once out on the grass
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The Blues stars were all smiles once out on the grassCredit: Getty
The pool is fitted with an underwater treadmill and cameras to help players recover from serious injury and monitor their progress.
Chelsea's players also use it for day-to-day recovery work.
This isn't the first time the club's training base has experienced disruption in recent months.
In August, the Blues called the police after £30,000 worth of camera equipment went missing from their Cobham base.
It was said that the equipment may have simply been mislaid and could reappear once club staff return from their summer breaks.
Chelsea' training ground has been their home since 2005, though it was only officially opened two years later.
Estevao became Chelsea's youngest-ever Champions League goalscorer against Ajax on Wednesday
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Estevao became Chelsea's youngest-ever Champions League goalscorer against Ajax on WednesdayCredit: Getty
The 140-acre site is home to the club’s men’s and women’s teams and, since the final phase was completed in 2008, its academy and football in the community department.
Interestingly, a third of the indoor facilities at the club are underground.
This is due to the terms of the planning permission, which state that no building can be taller than those in the surrounding area.
Sunderland awaits
After emerging unscathed from their training ground incident, Chelsea will be looking to keep up their recent good run of form.
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They thrashed Ajax 5-1 in the Champions League on Wednesday, in a much-changed side from the team that beat Nottingham Forest 3-0 last weekend.
The Blues currently sit fifth in the Premier League table on 14 points, level with their opponents Sunderland, who are two places below them on goal difference.