MINNEAPOLIS (WCCO) — A pipe bomb was found Thursday on the second floor of a Mayo Clinic parking ramp, police say.

No one was hurt after family members of a Mayo Clinic patient found the device in the Generose Building parking ramp at about 11 a.m. Thursday at St. Mary’s Hospital, according to authorities. No arrests have been made, but police said the woman who had been driving the car with the pipe bomb in the trunk admitted her son had made the explosive months ago.

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Those who found the pipe bomb, which weighed 50 to 60 pounds, offered to drive the device off the property, but authorities said no.

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Neighboring buildings were not evacuated, but patients and employees weren’t allowed into the ramp. The bomb squad from Bloomington arrived at 2:20 p.m. and with the Jaws of Life, opened the trunk of the car.

The bomb was 3 feet long, made of heavy gauge metal and had a 1-foot-long wick on one end. A robot took the device out of the ramp and into a container that was then shuttled to a quarry outside of town for detonation.

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The all-clear came at 5:20 p.m.