A firefighters uses a hose and works to put out massive flames in the San Bernardino Forest. Photo courtesy Brandy Nichole Photography

SAN BERNARDINO COUNTY (KABC) -- Flood waters overtook a couple hiking near Mill Creek Crossing in Forest Falls Tuesday afternoon, San Bernardino County Fire spokesman Chris Prater said.An off-duty sheriff's deputy heard the couple calling for help. He was able to save the young woman, but the man was swept away.The body of the victim, a Rancho Cucamonga man in his 20s, was found shortly after 7 p.m., Prater said.A powerful storm cell packed with heavy rain and hail moved through, creating a quick-moving river runoff that trapped the young couple.Parts of the Inland Empire saw flash-flood warnings Tuesday as Riverside and San Bernardino counties were pelted with hail.A flash-flood warning were in effect for Riverside and San Bernardino counties for most of the day.A thunderstorm producing heavy rain between Hesperia and Apple Valley caused flash flooding and mudslides.Residents were warned that excessive rainfall could cause flash flooding or mudslides, particularly within the Lake Fire burn area.The Lake Fire, which erupted on June 17 in a remote area of the San Bernardino Mountains, burned over 30,000 acres.The NWS said most flood-related deaths occur in automobiles and warned people not to attempt to cross water-covered bridges, dips or low-water crossings.