Emergency services evacuated homes in north Oamaru on Monday night after reports of a suspected gas leak at Quality Bakers.
At 11.30pm, emergency services were called to the Ayr St bakery and evacuated residents in the surrounding 150m of Orwell and Weaver Sts.
Chief Fire Officer Steve Couper, of the Oamaru Volunteer Fire Brigade, said up to 30 residents were evacuated to the Waitaki Community Recreation Centre.
''Our biggest worry at the time was the people around there, so we arranged to evacuate several households,'' Mr Couper said.
''We got the rec centre opened up. We sent them up there until we were able to ascertain it was safe.''
Gas testing came back negative, but Mr Couper said early indications pointed to the activation of a safety ''shut-down button'', which set off ''massive jets'' of water that could have been mistaken for (looking, or sounding, like) a gas leak.
''When that's activated - usually when there's a [gas] leak - the deluge system starts,'' Mr Couper said.
''We were pretty concerned there at the time . . . they have a substantial, stationary lpg cylinder down there. It's about 25 tonnes, so it's reasonably large.
''We went through, lifted all the manholes, tested them and found no reason to believe there was anything lying in the manholes or around houses.''
Rockgas, an Oamaru Quality Bakers engineer and police assisted the Oamaru Volunteer Fire Brigade with the evacuation and investigation.
Police were making inquiries yesterday to determine the cause of the activation.
