Two pedestrians were struck and critically injured outside Mountain View High School in Marana Unified School District tonight while leaving graduation ceremonies, authorities say.

 A woman who was in a wheelchair and a man who was with her were struck and suffered life-threatening injuries, said Capt. Adam Goldberg of the Northwest Fire District. Both are described as elderly.

 The woman in particular is in "extremely critical condition," Goldberg said.

 The accident occurred shortly before 9:30 p.m. on Thornydale Road south of Linda Vista.