Rotting beams caused the collapse of a deck which injured several people at an evening party in Chilmark last Thursday night.

Chilmark building inspector Leonard Jason Jr. made a visit to the home on Friday morning and inspected the damage. "It was a combination of too many people on the deck and it was rotted where it let go," Mr. Jason told the Gazette yesterday.

At approximately 6:45 p.m., an outside deck loaded with people collapsed during a cocktail party. Emergency medical technicians, firemen and other public safety workers from around the Island hustled to the scene at Clam Point Cove Road; the house belongs to Gayle K. Lee. At least nine people were transported by ambulance to the Martha's Vineyard Hospital emergency room. Several more were treated for abrasions, cuts and bruises.

Mr. Jason said the deck was at least 30 years old and the building of the house precedes the era of building inspections.

The building inspector urged anyone who has an outside deck to have it inspected at least annually. "People should be aware they need to maintain all wooden structures. Every year they should take a walk around their homes and look for rot," Mr. Jason said.

If a homeowner doesn't feel qualified to do an inspection or could use help, Mr. Jason said a structural engineer can be hired to take a look. There are a number of structural engineers on the Island capable of doing such an assessment. Just being more familiar with what lies beneath most outside floors can avert an accident like the one that happened Thursday night, Mr. Jason said.

The Martha's Vineyard Hospital staff worked well into the night tending to patients involved in the accident. Rachel Vanderhoop, hospital spokesman, said: "We were once again reminded of our good fortune to have such highly trained rescue personnel on the Island. Martha's Vineyard Hospital and its staff are proud to be among those who joined in the incredible effort that resulted in such a positive outcome."