ORLANDO, Fla. — Federal investigators on Monday blasted SeaWorld Parks & Entertainment for allowing its animal trainers to work with killer whales without adequate protection, following a six-month investigation into the violent drowning of a trainer at SeaWorld Orlando.

Investigators with the U.S. Occupational Safety and Health Administration recommended that SeaWorld trainers never again have direct contact with Tilikum, the six-ton killer whale who drowned trainerDawn Brancheauon Feb. 24. But they also recommended that trainers not be permitted to continue swimming or working in close contact with the company’s smaller killer whales — unless SeaWorld implements new safeguards.

The agency proposed fines totaling $75,000 for SeaWorld, which generated approximately $1.4 billion in revenue last year.

“”SeaWorld recognized the inherent risk of allowing trainers to interact with potentially dangerous animals,””Cindy Coe, the OSHA administrator in charge of the Southeast U.S., said in a prepared statement. “”Nonetheless, it required its employees to work within the pool walls, on ledges and on shelves where they were subject to dangerous behavior by the animals.””

In its statement, OSHA added that its probe “”revealed that SeaWorld trainers had an extensive history of unexpected and potentially dangerous incidents involving killer whales at its various facilities. … Despite this record, management failed to make meaningful changes to improve the safety of the work environment for its employees.””

SeaWorld immediately said it would challenge the findings.

“”SeaWorld disagrees with the unfounded allegations made by OSHA today and have already informed the agency that we will contest this citation,”” the company said in a written statement. “”OSHA’s allegations in this citation are unsupported by any evidence or precedent and reflect a fundamental lack of understanding of the safety requirements associated with marine mammal care.””

The closely watched federal investigation, sparked by the worst tragedy in SeaWorld‘s 46-year history, ultimately concluded with OSHA citing SeaWorld with one “”willful”” workplace-safety violation.

As part of that citation, the agency singled out interactions with Tilikum, an animal investigators said had “”known aggressive tendencies”” because he was one of three killer whales who drowned another trainer at a aquarium nearly 20 years ago. Though SeaWorld has barred trainers from swimming with Tilikum since acquiring him shortly after the 1991 tragedy, OSHA cited the company for still allowing “”unprotected contact”” by permitting trainers to work with the animal from the tank edges and shallow underwater ledges.

Dawn Brancheauwas laying face-to-face with Tilikum on one of those underwater ledges when the killer whale grabbed her by her long ponytail and pulled her underwater. OSHA recommended that trainers not be permitted to work Tilikum again without a physical barrier between them.

OSHA also said trainers were exposed to similar risks from the rest of SeaWorld‘s killer whales. But the agency’s recommendation for work with the remaining orcas was less strict than with Tilikum: OSHA said trainers should not be allowed to swim with the remaining orcas unless they are protected by a physical barrier or “”through the use of decking systems, oxygen supply systems or other engineering or administrative controls that provide the same or greater level of protection for the trainer.””

The recommendation appears to leave an opening for SeaWorld to allow its trainers to re-enter the water with killer whales once the company completes its own safety review and implements procedural or equipment changes.

SeaWorld said OSHA’s conclusions stand in “”stark contrast”” the findings of its from own internal probe, which the company said has been reviewed by a panel of outside experts from other marine parks and aquariums.

“”The safety of SeaWorld‘s killer whale program was already a model for marine zoological facilities around the world and the changes we are now undertaking in personal safety, facility design and communication will make the display of killer whales at SeaWorld parks safer still,”” SeaWorld said. “”It also is important to note that while maintaining a safe environment for our trainers, the demands of humane care require our zoological team to work in close physical proximity to these animals. Our trainers are among the most skilled, trained and committed zoological professionals in the world today. The fact that there have been so few incidents over more than 2 million separate interactions with killer whales is evidence not just of SeaWorld‘s commitment to safety, but to the success of that training and the skill and professionalism of our staff.””