Three teenage boys from Thorold, Ont., were suspended about 115 feet above the Welland Canal for about an hour before they were rescued early Tuesday morning in a stunt that closed the canal and risked the lives of the teens and their rescuers, authorities said.

The three youths – ages 16, 17 and 18 – ignored posted warning signs as they climbed onto a narrow beam on the Allanburg Lift Bridge that took them over the canal.

“The three of them rode the bridge up,” Constable Derek Watson of the Niagara Regional Police said.

The trio called out to a passing ship below, whose occupants called authorities at about 1:30 a.m. That call for help brought the Niagara Regional Police, the Thorold Fire Department and the Niagara Falls Fire High-Angle Rescue Team to the scene.

“I don’t know if they were yelling because they were in distress or they were just whooping and hollering,” Watson said.

The high-angle rescue team secured the three teens before lowering the bridge, authorities said.

The rescue forced the St. Lawrence Seaway Authority to close the canal for about three hours, authorities said later in the day.

Officials were quick to point out the risks for both the teens and the trained emergency personnel who rescued them.

“If we’re talking a 35-meter fall, death certainly would be a possibility,” Watson said, adding that the teens also could have hit something in the water or been knocked out and drowned.

Authorities said the three young men ignored warning signs.

“These signs are posted for a reason,” Watson said. “In this particular case, we had a bridge with moving parts. These kids need to realize that they’re putting emergency personnel at risk as well.”

Officials estimated that the economic cost of closing the canal for an hour and a half exceeded $5,000, and that doesn’t include the cost of the rescue.

All three youths were charged with “mischief over $5,000.” The 18-year-old was charged as an adult, while his two companions will be treated as youthful offenders. Police did not release their names.

All three were released to their families.