Orlando , Florida ( CNN ) -- A federal hearing began Monday to determine whether SeaWorld Orlando should be charged with a willful violation in the 2010 death of killer whale trainer Dawn Brancheau . As witnesses took the stand inside the Seminole County Courthouse in Sanford , Florida , members of People for the Ethical Treatment of Animals , or PETA , demonstrated outside . Monday was the first day of the hearing , which will resume at 9 a.m. Tuesday and is expected to continue all week . In February 2010 , as park guests watched in horror , Brancheau , 40 , was pulled into a SeaWorld pool and drowned by a 12,000-pound killer whale named Tilikum . Brancheau had been sitting on the Shamu Stadium 's pool edge during a private show . After a lengthy investigation , the Occupational Safety and Health Administration -- the federal agency that works to prevent workplace injuries -- cited SeaWorld of Florida in August 2010 for willfully endangering employees by not taking proper safety precautions . `` SeaWorld recognized the inherent risk of allowing trainers to interact with potentially dangerous animals , '' Cindy Coe , OSHA 's Atlanta regional administrator , said in a statement . `` Nonetheless , it required its employees to work within the pool wall , on ledges and on shelves where they were subject to dangerous behavior by the animals , '' she said . The citation said the park allowed its employees to work with Tilikum , a whale with `` known aggressive tendencies '' who was involved in the 1991 death of a trainer at a Vancouver , British Columbia , marine park . The theme park did not provide barriers , decking , oxygen supply systems or other types of protection for the trainers , OSHA said . SeaWorld spokeswoman Becca Bides disagreed , saying , `` These allegations are completely baseless , unsupported by any evidence or precedent , and reflect a fundamental lack of understanding of the safety requirements associated with marine mammal care . '' SeaWorld contested OSHA 's findings and is presenting evidence to the OSHA Review Committee , a separate government agency , at this week 's hearing in Sanford , northeast of Orlando . OSHA Review Committee Administrative Judge Ken Welsch is presiding over the hearing , in which both sides are presenting evidence and witness testimony . In his opening remarks on Monday , OSHA attorney John Black said SeaWorld allowed their trainers to take a calculated risk by working with killer whales that have the potential to cause harm or death to those who get close . Trainers are required to sign a document that acknowledges that they have read the standard operating procedure manual and acknowledge the calculated risk . Black called the document a release waiver and argued that the park 's training for the handlers was not enough . SeaWorld 's attorney said the handlers ' training is only one component , noting that the animals are trained , too . `` It goes hand in hand , '' said Carla J. Gunnin Stone . It 's unclear if OSHA 's attorneys will present surveillance video showing Brancheau 's death . Her relatives have fought to keep it sealed . U.S. District Judge Gregory Presnell on Thursday denied the Brancheau family 's request to keep the tape from being released or used at the hearing . `` We can not comment on what may or may not be presented ( during the hearing ) , as that depends not only on our own attorneys but also on any rulings issued by the judge in the case , '' OSHA spokesman Michael Wald said . Since the accident , SeaWorld has restricted all trainers from entering the water with killer whales until further notice , though Tilikum has returned in a theme park show called `` One Ocean . ''
After death of killer whale trainer , he said SeaWorld did n't take proper action . Dawn Brancheau died during the 2008 show . SeaWorld says ` ` allegations are completely baseless '' It 's unclear whether video of Brancheau 's death will be shown at this year 's show .