The video shows Stuart Holt - dressed in a pristine white work shirt - jumping into the roadside drain after spotting the little birds, which had fallen in and become trapped.
He gently lifts them out, one at a time.
They are then showing running to safety in the undergrowth, where their frantic mother was waiting off-camera.
The scene enfolded near an industrial estate in Pittsburg, USA, where Stuart is currently working.
Stuart, 38, who works for multinational design and publishing company Partner Plus Media, has lived in New York for 15 years and his wife Laura is American.
But he is originally from Fleetwood.
He and his colleague were driving when they saw the chicks and their mum safely cross the road – but then three of the chicks fell in the drain.
Stuart saw it happen and decided to help, while a colleague filmed him on a mobile phone.
The video was uploaded onto various social media platforms after it was shared by Canadian Instagram influencer, Life Of Sterling Newton.
Stuart, who had only just begun his deployment in Pittsburg, said: “We stopped to let them all cross but then saw then fall in.
"I knew we couldn’t just drive off, I had to get them out.
"The mother was making a dreadful noise, she was distraught.
"I lifted the drain cover, which was quite heavy, and got them out.
"I was in my work clothes but I didn’t care – they were getting out of there!”