A boiler malfunction at South Peninsula Hospital last Thursday afternoon caused an explosion that could be heard throughout much of the building and set off an alarm forcing the evacuation of several patients.

The explosion occurred at around 2 p.m, as one of the hospital's two new100-horsepower boilers ignited, said hospital spokesperson Derotha Ferraro. No one was injured and Ferraro categorized it as a release of pressure or a backfire. No flames were present, she said. But it did release enough soot into the boiler room to set off alarms.

"It was scary, but it was an opportunity to practice (emergency procedures)," she said. "In house, it went smoothly, as far as that goes."

Staff evacuated the entire long-term care unit in about six minutes, Ferraro said. Other patients and some staff were also evacuated, but everyone was back inside within 30 minutes of the alarm sounding, she said.

Representatives from the fire and police departments also were on-site when the explosion occurred, she said.

The boiler has since been fixed and has been running since Saturday without incident, Ferraro said. The reasons behind the accident are yet to be officially determined.

Ben Stuart can be reached at ben.stuart@homernews.com.