Cleaners are also alert for security problems, like vandalism, signs of theft (forced windows or doors, missing computers or stock), blocked fire escape routes, lights or fire alarms not working, or trespassers. When these occur, the cleaners promptly notify their sites' Security Officers and Site Supervisors. Janitors know how to keep themselves and their sites safe, by immediately removing hazards like broken class, spilled fluids, and waste from kitchens and bathrooms, and by checking hand rails, floor mats, stairs, automated doors, escalators, elevators, intercoms, and plumbing.