Philadelphia's Ride the Ducks tour boats were abruptly shut down on Wednesday evening.
A statement on the company's website announced the decision:
"As of October 5, 2016, Ride The Ducks Philadelphia has suspended operations indefinitely.
"Please direct any inquiries to firstname.lastname@example.org or call 678-456-5328. We regret having to close our operation and send good wishes and brotherly love to the people of Philadelphia."
Amphibious tourist vehicles have been involved in accidents causing injury, including a Texas tour boat that mowed down and killed a pedestrian in 2015. In September 2015, four international students were killed in a duck boat crash in Seattle, Fox13 Seattle reported at the time. In 2010, a duck boat was struck by a barge in the Delaware River. Two people were killed.
The National Transportation Safety Board last tracked Ride the Duck's crash data in 2008, Billy Penn reported. Between 2006 and 2008, Ride the Ducks reported 32 accidents that did not lead to injuries to the NTSB.