Grantham, NH – By SONIA SCHERR Valley News

GRANTHAM – The fatal explosion at a platform tennis court three months ago was caused by propane gas leaking from tubing underneath the court and igniting when the heating system was turned on, state officials said.

The state will not assign responsibility for the Jan. 5 blast, which killed one man and severely injured two others in Eastman, a recreational community off Route 10.

“It’s an unfortunate incident, but it doesn’t rise to the level of criminal charges,” New Hampshire Deputy Fire Marshal Bill Degnan said in an interview yesterday.

The explosion occurred because of a crack in the flare nut connecting copper piping to the shut-off valve for the left propane heater, according to the state report. The crack caused the piping to become loose and leak propane gas, which became trapped under the raised platform because of the high snow surrounding it.

The heating system is used to melt snow from the tennis court. When an Eastman resident turned on the switch that starts the heating system, one of the heaters probably ignited the trapped propane gas and triggered the explosion, the report said.

The blast ripped apart the tennis court, killing James M. Owen, 64, who was buried in several feet of snow. Morton Shea, 68, and Anthony Crecca, 61, suffered broken bones, cuts, lacerations and blunt trauma. A fourth man, Robert Kessler, 64, received slight injuries and was treated at the scene. All four men had volunteered to remove snow from the court.

Degnan said investigators don’t know what caused the crack in the flare nut, although it could have resulted from a defect in the part, too much tightening or something hitting it. He said the state examined the maintenance and installation of the system as part of its investigation, but didn’t find any problems that would have directly contributed to the incident.

He said there was some question as to whether the heaters were designed for use under the tennis court. The heaters became confined after snow packed against the openings in the raised platform. The heaters are not supposed to be used in confined spaces, Degnan said.

Ryder said the insurance companies would investigate whether the heaters should have been installed. The leak occurred several feet away from the heaters, which were manufactured by L.B. White Co. of Wisconsin. The company couldn’t be reached for comment, but in an earlier e-mail message, Director of Engineering John Tomlinson said the state’s investigation showed that the heaters weren’t involved.

Tomlinson said L.B. White’s heaters had an excellent safety record and hadn’t been involved in any fires or explosions leading to injury or death.

Degnan couldn’t say whether the accident might have been prevented. “That’s hard to tell,” he said. He did urge people to leave the area and call the fire department if they smell propane. Several Eastman residents smelled propane at the court in the days before the explosion, the state’s report said.