The married couple had driven their two vehicles onto the Mühlheim car ferry to make the trip to Maintal-Dörnigheim around 8 pm. The husband's car pulled in first, but the couple was concerned that the second car – carrying two children and the family dog – would not fit on the ferry because it blocked the gate from closing.
“The husband in the leading vehicle was of the opinion that his wife's car could not be transported, though the ferry captain had said there was enough room,” police said in a statement.
The man directed his wife to back her car off of the ferry, but it had already left the shore and the car plunged into the river, where it floated partially submerged.
“The woman, both children and the dog were able to get themselves to the shore uninjured,” the police said.
Meanwhile helpful passersby secured the vehicle with tow ropes until the fire department arrived to fish it out of the river.
Harbour police are investigating the accident.