Polk County authorities said a man was critically injured Tuesday after an explosion at a house where suspicious chemicals were found. The man, whose identity was not released, was airlifted to Regions Hospital in St. Paul for severe injuries to his hand and burns to other body parts, according to the Polk County Sheriff's Office. The incident was reported at 8:15 p.m. Dec. 4 at a home in the town of Sterling near Cushing — a community about 15 miles north of Taylors Falls, Minn., — for a man who had "blown his hand off," according to a sheriff's office news release. Cushing first responders and firefighters responded before requesting the airlift.