A Hawaii-bound flight departing Denver Sunday was rerouted to San Francisco due to the aircraft's problematic toilets.

United Airlines flight 1219 was redirected after it had already flown halfway over the Pacific Ocean to reach its intended destination, KDVR reported. The plane's bathrooms, however, had suffered a "mechanical issue." The aircraft was, therefore, diverted to San Francisco. This added an additional eight hours to its arrival time, according to Fox News

"Flight 1219 from Denver to Lihue, Hawaii diverted to San Francisco for a mechanical issue with the lavatories," a United Airlines spokesperson said in a statement issued to International Business Times. "Upon arrival in San Francisco, we switched to a new aircraft and resumed service to Lihue."

United Airlines sent an apology letter to all passengers on board. 

"I am very sorry that our lavatories had reached capacity while Flight 1219 was en route to Lihue," United Airlines officials said in a letter addressed to passengers, according to KDVR. "A decision was made to turn back and land in San Francisco where arrangements were made to change planes. I can appreciate that this experience was disappointing and unpleasant."

"We regret the unexpected delay and inconvenience this caused you. Your satisfaction is important to us so I hope you will accept our offer of apology on the next screen," the airline continued. 

It had not yet been confirmed why the bathrooms on United flight 1219 weren't adequately attended to in Colorado ahead of its departure. The airline, however, intends to appease customers that faced the lengthy delay.

In addition to sending an apology letter to affected customers, United Airlines is expected to gift all passengers with 10,000 bonus miles or a $200 voucher that can be used when booking a future flight with the air carrier, KDVR reported. 

This isn't the only United Airlines that has been rerouted recently. The air carrier diverted a Paris-bound flight Monday to Dulles International Airport in Virginia after a passenger suffered a medical emergency, according to the New Jersey Herald. Details regarding the passenger's medical issue were not confirmed.