RENO, Nev. >> Fire ripped through the second deck of a docked tourist cruise boat under repair at Lake Tahoe on Tuesday, severely damaging the popular paddle wheeler and injuring two workers on board before crews extinguished the flames that sent a plume of black smoke high above the Sierra waters.

The 144-foot Tahoe Queen can hold up to 300 passengers, but only the workers were on board when the fire broke out about 8 a.m. at Zephyr Cove on the southern end of the lake about 60 miles south of Reno.

One contractor on a construction crew that was painting and welding on the boat suffered a sprained back when he jumped from the top deck to escape the smoke and flames, said Eric Guevin, fire marshal for the Tahoe Douglas Fire Protection District.

The other suffered mild smoke inhalation, he said. Both were treated at the scene and refused further care, he said.

Firefighters took a little over an hour to extinguish the blaze on the three-level boat, which has an open deck on top and is operated by a motorized paddle wheel.

Flames could be seen from U.S. Highway 50 along the forested shoreline and smoke was visible miles away from the lake that straddles the Nevada-California line.

“The whole cabin, every window, there were flames shooting out,” said Zach Hastie, a trail guide at nearby Zephyr Cove Stables.

“The fire was so hot it was sending the smoke cloud straight up in the air,” he told The Associated Press.

Guevin said an unspecified number of other workers on the boat at the time escaped injury. He said the worker who strained his back was on the roof of the pilot house atop the boat when the fire started.

“He saw his exit was blocked by smoke and flames, so they went over the railing,” he said.

U.S. Coast Guard inspectors from San Francisco arrived Tuesday afternoon to begin investigating the cause of the fire, Guevin said. He said the vessel was still afloat, but suffered severe damage. It wasn’t immediately clear if it could be salvaged.

The Tahoe Queen holds up to 300 passengers when it’s running, but tours have been suspended since winter due to the lake’s low water level and the boat was undergoing retrofitting. Nearly 300 passengers and a dozen crew members had to be rescued in August 2014 when it hit a sand bar and became stuck about 600 yards off the shore of South Lake Tahoe, California.

On Tuesday, a Coast Guard crew, fire district boat and locals at the Zephyr Cove resort circled the paddle wheeler soon after the fire began with floating booms to capture any debris, said Kate Warner, the fire district’s office manager.

Guevin said a call to a hazardous materials team was canceled, and there was no indication of any fuel or other leakage into the mountain lake.

The lake’s water quality is strictly regulated by a congressionally-mandated bistate compact, the Tahoe Regional Planning Agency.

The first lakefront development approved by the agency in 30 years broke ground Monday next to Edgewood Tahoe Golf Course in Stateline, where the Tahoe Beach Club plans 143 condominiums priced from $1 million to $4.5 million.