LOS ANGELES—A doctor has testified that a UCLA research assistant who died after being injured in a lab fire suffered burns over almost half her body.

The doctor who treated Sheharbano "Sheri" Sangji described the extent of her injuries Friday as part of a hearing to determine whether her supervisor should stand trial.

Chemistry professor Patrick Harran is charged with willful violation of an occupational safety and health standard causing the death of an employee. He maintains that the 2008 fire was an accident.

In his testimony, Dr. Peter H. Grossman said Sangji told him that a chemical she was working with spilled and burst into flames, igniting her clothes. She underwent several procedures for her burns before being declared brain dead.

Harran faces 4 1/2 years in prison if convicted.