Rush University Medical Center posted this photo on its Twitter account Monday. The message was apparently left for a patient. View Full Caption Twitter/RushMedical

NEAR WEST SIDE — A patient at Rush University Medical Center received a pleasant surprise this weekend: a personal message in the snow.

"HI MOM GOD BLESS U!" can be seen stamped onto the snow-covered roof of an at-least nine-story parking garage in a photo the hospital posted on its official Twitter account Monday. The "o" in "mom" was made into a smiley face, and the message spanned the width of the roof.

Angela Washek, a 26-year-old surgical nurse, said she and her fellow nurses saw four people on the roof of the parking garage Saturday night. She assumed they were just goofing around.

But around 1 a.m. Sunday, Washek noticed the message.

"It made everybody's night so much better, seeing a good message like that," said Washek, who's worked at the hospital for two years. "Sometimes we only see the bad side in healthcare. We don't get to see the good that we do sometimes."

It was unclear as of Monday night for whom the message was intended.