The hamlet of Swalwell in southern Alberta was ordered to evacuate, and a state of local emergency declared, after a train collided with a propane tanker truck."Avoid the area. Evacuate immediately. Follow the directions of local authorities," an information alert issued 4:33 p.m. Monday read. The alert was updated to a state of local emergency at 9:18 p.m.The collision happened at 2:55 p.m.Traffic was blocked at Township Road 302 and Railway Avenue.CN Rail said propane from the truck leaked out but no goods from the train, which was carrying freight containers, spilled.There were no injuries or fires immediately reported, CN Rail said. Both fire crews and CN police were on scene."Both vessels of the propane truck have been impacted. The severity of the leak is unknown at this time, but due to the nature of the product every precaution is being taken," a news release posted to Kneehill County's website read. "Please continue to avoid the area."Kneehill County stated that fire department members went door to door to ensure residents left safely and that around 100 people were displaced.County Reeve Jerry Wittstock said it's not unusual for trains to derail in the area, but that this is the most serious incident of the kind he's seen.Wittstock said around 68 homes are located in the hamlet, and some homes are near the railroad tracks.Evacuees were being asked to register at a reception centre set up in the cafeteria at the Prairie Bible Institute, 350 Fifth Avenue North in Three Hills, Alta., as they would not be able to return home overnight. The reception centre would be open until 10 p.m., and those requiring accommodations after that time were asked to call 1-866-443-5541.The county said there would be a further update at 9 a.m. Tuesday.Swalwell is located about 90 kilometres northeast of Calgary.