Three years after the Deepwater Horizon oil spill, oil giant BP will have its day in court.

The federal trial started Monday in New Orleans. Government lawyers are trying to prove that BP was grossly negligent and that one word "grossly" could mean billions more in fines for the oil company.

The second phase of the trial will determine the environmental damage and will put a price tag on every animal killed by oil.

Environmental groups want to see fines in the range of $25 billion.

"It should be the maximum end of the fines and the damage done here is real, both to the environment and to the people, and BP should not have the chance to get off cheaply on this," said Brian Moore, National Audubon Society.

A total of 60 lawyers will be present in the courtroom each day.  There are so many they had to make a seating chart inside federal court.