MOBERLY, Mo. (AP) _ Storms raked the southern Plains on Tuesday with tornadoes and strong winds, killing an adult and two children and injuring about a dozen people.

In north central Alabama, high winds overturned a boathouse on the Coosa River, killing a 28-year-old woman, her 4-year-old niece and 8-year-old nephew. Four others family members were critically injured.

The family was on a July Fourth boating excursion and sought shelter from bad weather in the boathouse near Ragland, 30 miles northeast of Birmingham.

In northeast Missouri, a tornado hit the main street of downtown Moberly, blowing the roof off City Hall, downing power lines and breaking gas lines, police said.

Roads were blocked by fallen trees and power lines, and police cordoned off much of downtown in this community of 13,000 residents.

About 100 homes were hit, although early reports indicated the damage was light to moderate, Assistant Police Chief Dennis Cupp said. He said dozens of downtown businesses also were damaged.

An officer was stationed in City Hall to guard records, he said.

About five to 10 people were treated for minor cuts and bruises and released, said Moberly Regional Hospital nursing director Kerri Jenkins.

Clete Garrott, surveying the damage to his vacuum repair shop, said the tornado moved over his house about two miles southwest of Moberly before touching down.

``We'll survive, but the building won't,'' he said.

Tornadoes also were reported in Linn County to the northwest and in Shelby County to the northeast. The twisters were part of a storm system that pummeled regions from southwest Kansas to northeast Missouri.

``I'm eating dinner at about 5:45 and all the sudden I saw the debris flying,'' said Jerry Clark, who farms near Browning in Linn County.

Some property damage was reported, including the destruction of a 100-year-old school house.

``It was called the Little Red School House,'' said Ted McCollum, a supervisor with the Linn County Highway Department. ``They were planning to have a celebration and dedicate it next year, but she's totally gone now.''

A tornado that touched down in Shelby County to the northeast of Moberly blew down trees and damaged barns, a sheriff's dispatcher said.