PROVIDENCE, R.I. (AP) — For one sparkling minute each night, skyscrapers, tugboats, hotels, a yacht club and police cruisers send a blinking goodnight message to sick kids inside a children’s hospital.

A gesture that began with a single light six years ago has become a nightly display along the Providence River — and a highly anticipated ritual — inside Hasbro Children’s Hospital.

“It’s special to know that people I don’t even know will take the time” to flash the lights, said 13-year-old Olivia Stephenson, who has been admitted to the hospital three times since June, most recently last week.

To thank the invisible strangers shining their lights at her and fellow patients, she blinks her own flashlight back toward the downtown skyline, using a two-flash response that means “thank you.”

“They don’t know me; they could skip the step of flicking the lights, but they do it anyway,” she said after seeing the Good Night Lights display for the first time in late August. “I hope they saw the thank you.”

Some of Providence’s bigger hotels have installed permanent signals that automatically turn on flashy messages at 8:30 p.m., to the delight of giddy toddlers and older children who can spot them from their windows.

But most of the lights are hand-held. One volunteer group gathers near the top of a 28-story office building to flash their lights. The farthest signal comes from a church group blinking from a dark shoreline 2 miles downriver in East Providence.

Olivia began her summer looking forward to lazy days at the beach and pool, but she collapsed the day after school got out, and her life turned upside down. Doctors diagnosed her with lupus, a chronic autoimmune disease.

She was adjusting to a more complicated life — diet and lifestyle restrictions, medication that puffed up her face — when chest pains took her to the hospital again in August. Tests found big blood clots in her lungs.

She saw Good Night Lights for the first time after she was released from a five-day stay in a windowless intensive care unit.

“It’s so nice to see a genuine smile on her face, because it’s been a while,” said her mother, Beth Stephenson, who has spent the hospital visits sleeping on a chair by her daughter’s side. “It’s genius. It totally brightens the kids’ spirits and it doesn’t even really cost anything.”

The idea began with the hospital’s resident cartoonist, Steve Brosnihan, who has spent 26 years regaling sick kids with on-the-spot drawings and word games. Brosnihan, who gets to the hospital by bike or bus, noticed one day in 2010 that he could see his route home from inside the six-story hospital. Using his bike light and flashlights, he began sending simple messages tailored to individual kids. Late last year, he appealed to local businesses to send a joint message: Goodnight, Hasbro, using four flashes to represent each syllable.

The first business to participate was The Hot Club, a waterfront nightclub and restaurant. Along with flashing its large neon sign, patrons gather on the deck each night, even in cold weather, to wave their flashlights and cellphones. Following the nightclub were the tugboats of the Providence Steamboat Company. They shine their powerful searchlights at the hospital and occasionally blow their horns. A yacht club, restaurants and police officers have also joined in.

About two dozen kids who can range in age from 2 to 20 are in the hospital on any given night.

“The first time a kid sees this, when it happens, they’re like, ‘Are you kidding? That’s for me?’ There’s a joyful surprise in it,” Brosnihan said.

The anonymity of the exchange is what Brosnihan finds most beautiful.

“No one knows who’s on the other side of the gesture,” Brosnihan said. “People often say, ‘I get goosebumps hearing about this.'”

Brosnihan said he dreams of what he calls the “minute of magic” catching on in other cities with children’s hospitals. But he also notes that Providence’s pediatric hospital is peculiarly suited to the phenomenon because it has an open view of a harbor and the city’s downtown skyline.

Once Olivia gets back to being a “regular girl” — she aims to return to her school in the town of Lincoln in January — she wants to help work with younger kids and expand the Good Night Lights ritual.

“It’s special. I’m not going to forget this experience,” she said.

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