Police were contacted at 11.54pm yesterday ( July 12 ) by North West Ambulance Service after they were called to a report of two people injured at an address at Teasdale Road, Barrow.
One man, 19, had sustained a suspected broken arm, while another, 57, had sustained life-threatening injuries.
Initial investigations were carried out and the 19-year-old man was arrested on suspicion of causing grievous bodily harm with intent and escorted to Furness General Hospital for treatment.
The man, 57, was taken to hospital in Preston where he remains in a critical condition.
A woman at the scene, 54, was also arrested on suspicion of causing grievous bodily harm with intent.
Investigations remain ongoing. Residents may notice a larger-than-normal police presence in the area as a result.
Anyone with information is asked to contact police on 101, referring to incident 355 of July 12.
Alternatively you can contact Crimestoppers, anonymously, on 0800 555 111.