TULSA, Oklahoma - Less than 500 PSO customers are still without power in the Okmulgee area Monday after storms rolled through the community early Sunday.

High winds knocked out power to Muscogee Creek Nation Medical Center and around 5 a.m. Sunday.

The National Weather Service office in Tulsa says the damage was due to straight line winds.

A hospital spokesman said a generator system kicked in, powering up the entire hospital. The hospital is still open for patient care, and he says all services including the ER, are still available to the community.

Behind the hospital, Highland Park Manor Nursing Home also spent Sunday without power. There are 82 patients inside the nursing home, but their administrators tell me they've been able to function.

Administrators say they have portable generators to help patients in need. Dennis Crosby came to the nursing home Sunday to visit his mother in law when he heard about the outage.

"These people I really think they should be a priority as far as getting the power back on for them, and I'm sure they've been doing all they could do but it's been a lot of hours." Said Crosby.

PSO has been working throughout the day to restore power. Crews say the outage was caused when a tree fell on power lines.