As reported by the Charles County Volunteer Fire and EMS Associations:

At 8:47 a.m. this morning, Charles County 911 center received calls advising two vehicles were swept from the roadway on Prince Frederick Road at Swanson Creek on the Charles/Prince George's County line. 49 members including our Special Operations Division, Dive/Rescue Team, and mutual aid resources from PGFD responded to the scene. Hughesville Chief 2 (Matt Herbert) arrived, established command and assigned Special Ops Chief 17 (Mills) the "Rescue Group". As fire/EMS resources arrived it was confirmed two persons were off the roadway one male on the roof of his vehicle and a female near her vehicle hanging onto a tree limb. In addition, rescuers from Waldorf Truck #12 made a rescue of a male subject that was making an attempt to rescue the two from their vehicles; the current was too strong for anyone to attempt any rescue on foot with no PFD or life saving equipment. Air Boat #8 from the Tenth District VFD launched and made the successful rescues of the two occupants, both evaluated on scene, female transported to CRMC for check-up. All Fire and EMS units on scene for 3 hours, no other injuries reported.

Updated report from the incident:

Rescue Squad 2 was just clearing a call in which a large tree struck a house when the Charles County 911 center received calls advising two vehicle were swept from the roadway in the 5600 block of Brandywine Road. Rescue Squad 2 arrived on scene and was flagged down by a witness who observed the vehicle get swept off the road by the fast moving water. They were able to give Chief 2 a landmark on where the vehicles were last seen going into the woods. They advised a bystander was trying to help and was also stuck in the water. While Rescue Squad 2 members were getting prepared to assist with the water rescue, yelling could be heard from the victims who were trapped on top of vehicles. Chief 2 established command and assigned Special Ops Chief 17 to the "Rescue Group". As fire/EMS resources arrived it was confirmed two vehicles were off the roadway along with one Good Samaritan who tried to help prior to Fire/EMS arriving. Truck 12 from Waldorf was able to utilize the aerial stick and rescue the bystander who was stuck in a tree 80 feet from dry land. The male occupant was located on the roof of his vehicle and a female near her vehicle hanging onto a tree limb. The current was too strong for anyone to attempt any rescue on foot with no PFD or life saving equipment. Air Boat 8 from the Tenth District VFD launched and made the successful rescues of the two occupants. Prior to terminating command, Chief 2 had MSP Trooper 2 do a fly over as a secondary search to confirm no other occupants were stranded in the water. All Fire and EMS units on scene for 3 hours, no other injuries reported.