A blackout in one building on the White Memorial Hospital campus in Los Angeles early Tuesday has led to the evacuation of some patients, the L.A. Fire Department says. LAFD paramedics had to carry some down stairs to waiting ambulances because elevators weren't operating.

The LAFD said it was working with White Memorial staff to identify the patients who need to be brought to other hospitals after the Specialty Care Center went dark.

Patients on ventilators were topping the list, the department said. At first, 11 were chosen for evacuation.

In all, 30 patients were "deemed critical" and were being brought by LAFD ambulances to another hospital, the department said.

The rest of the patients in the facility, 211 of them, were classified as non-critical and were being moved to a different building on the campus, the South Tower, the department said.

The LAFD said 20 ambulances with firefighter paramedics and 22 fire companies were at the scene. 

It wasn't clear what caused the outage or whether it was related to Hilary, the storm that dumped heavy rain on the region Monday.

-- This is a developing story. Check back for updates.