Three people were hospitalised earlier this week after what was thought to be a carbon monoxide leak at Martins Wood Primary School in Stevenage.

Here's all we know so far about the major incident.

What happened?

Police, fire and ambulance crews were called to Martins Wood Primary School in Mildmay Road just after 1pm on Wednesday, June 12, following reports of a number of children and adults becoming unwell.

One adult and two children were taken to Lister Hospital by ambulance with suspected carbon monoxide poisoning, while a further six adults and nine children were assessed at the scene.

What was it like at the scene?

An anonymous parent who spoke to the Comet, described a chaotic scene at Martins Wood Primary School.

"The scene was chaotic. It was like a scene from a movie. At one point the sky went grey, there was every emergency service there, people crying, dads trying to fight to get in. It was horrible," she said.

"One mum jumped the tall fence to get to her child. There were children leaving the gates with sick bowls and draped in paramedics blankets.

"When all the children were let out a lot were crying because they witnessed their teachers and friends collapsing.

"As a parent I was scared, and the stress just kept increasing seeing children leaving the school, but having zero information about what was going on, how my child was, or why they weren't being let out."

What is the condition of those hospitalised?

In an update on Wednesday, Martins Wood Primary School confirmed that those taken to hospital were "not in a serious condition".

Then on Thursday, a school spokesperson confirmed: "The member of staff and two children who were taken to hospital have all now been discharged."

Was it carbon monoxide?

Despite initial confirmation that the incident was a suspected carbon monoxide leak, Martins Wood said this was not the case on Thursday.

"Today, the school was thoroughly tested and inspected by a Gas Safe Registered heating engineer, and carbon monoxide has not been detected in any area of the building," a letter to parents read.

"Medical tests have shown no evidence of carbon monoxide in their systems. All three incidents are now believed to be unrelated to each other.

"I would like to reassure you that we have carbon monoxide detectors at our school and these are fully operative."

Has the school had gas leaks before?

On Friday, a spokesperson for Ivy Learning Trust, which runs the school, made concerning revelations about previous gas leaks at the Mildmay Road site.

"There were two previous gas leaks at Martins Wood Primary School," the spokesperson told this newspaper.

"One in 2022, before the school joined Ivy Learning Trust, and a further one in 2023. On both occasions the school was temporarily closed for one day.

"Remedial works have since been carried out to replace a valve and there have been no further gas leaks on the premises.

"The systems were checked again by a Gas Safe Registered heating engineer yesterday."