A worker on a northwest Calgary construction site was hospitalized Thursday following a fall. An EMS spokesperson told CTV News that they were called to the site, in the 100 block of Roselake Street N.W., around 1:45 p.m. They located a worker who had fallen off the roof of a home under renovation and they transported them to hospital in serious, potentially life-threatening condition. An investigation by Occupational Health and Safety is underway into what caused the fall.