THE threat of a large explosion in St Peter’s Valley was still very serious this morning almost 20 hours after a gas cylinder caught fire at the Granite Products quarry.

A senior Fire Service officer said today that there was the potential of either a big fireball or the six foot by one foot acetylene cylinder turning into a ‘projectile’ and flying into the air.

Houses within 200 metres of the quarry were evacuated yesterday afternoon and the residents had to spend the night with friends or relatives.

Assistant divisional officer Mark Johnson added, however, that high explosives used for blasting were stored some distance away and the risk of them going up was limited.

He said his officers were treating the incident very seriously, as a firefighter in the UK was killed last month when a similar cylinder exploded.

‘From my point of view it could not be in a better situation,’ said Mr Johnson.

‘It is in a workshop with concrete walls, within a quarry, albeit near a main road.

It is not in the middle of St Helier.’ He added that every safety measure was being taken to keep the firefighters safe.