An equipment problem caused a New Jersey hospital to lose electicity for almost an hour Tuesday night.

According to Public Service Enterprise Group, Robert Wood Johnson Hospital in New Brunswick was lost from 10:15 p.m. to 11 p.m.

On Wednesday, two semi-trailers with electrical generators were seen hooked up in the hospital's loading dock.

A man operator the generators told PIX 11 News they are an "insurance policy," in case the building loses power again.

The state of the hospital's emergency generators is unclear.