Arson is suspected in a fire that destroyed a picnic pavilion early Tuesday morning on a lake in Chaska, and officials are asking the public's help in determining the fire's cause.

Firefighters responded to a call about 4 a.m. to find the Lake Grace Pavilion engulfed in flames. Fire crews from the Chaska and Victoria departments worked until about 8:30 a.m. to extinguish the blaze.

Most of the walls and the roof were destroyed, and the building is considered a total loss, according to a news release from the Chaska Fire Department.

The 1,800-square-foot lakeshore building, in the Jonathan area of Chaska, was renovated in 2016. Half of the structure was a picnic shelter with open walls, and the other half contained a kitchen and restrooms. It wasn't currently in use.

State and city fire marshals have concluded that the fire's origin looks suspicious, said Chaska Fire Chief Tim Wiebe.

"There was no heat source, no electrical, no nothing" on the site itself that could have started the fire, he said.

"The property at Lake Grace is a beautiful space for residents and their families," said Justin Scharpen, president of the Jonathan Association, in a news release. "Rebuilding will be among the association's highest priorities during 2019."

A reward of up to $2,500 is being offered for information that helps identify the people involved in starting the fire. Anyone with information is asked to call Chaska Fire at 952-227-7524. Tipsters may remain anonymous.

Katy Read • 612-673-4583