Date:September 22, 2004
Location: Fleur de Lys
Easting: 561800
Northing: 5552200
Latitude: 50°07′ 00″ N
Longitude: 56° 09′ 00″ W
Fatalities: 0
Injuries: 0
Source: Personal Observations by David Liverman; CBC news reports and web site.
A 15-tonne boulder rolled down-slope and impacted the residence of the Philpotts, Fleur de Lys. There had been of heavy rain for close to 24 hours in the area. Mr Philpott was at work, Mrs Philpott and her son were in the bedroom when she heard a noise described as being like thunder. She felt the whole house shake; she grabbed her son and ran out of the house as fast as possible. Once clear of the house she realized that a large boulder had fallen from the slope above and hit the rear wall of the house.
The Philpott house lies below the slopes of a small hill (Bear Hill on topographic maps) on the southeast side of the road on the entrance to the town of Fleur de Lys (Figure 1, 2). The hill rises approximately 30 m above the road, and extends for perhaps 200 metres alongside the road. The road is oriented southwest-northeast at this point. Three houses are built on flat ground at the foot of the hill. The Philpott house is the central of the three and lies below the highest part of the cliff. The slope in some places is bare rock, but elsewhere mature trees are common.
The hill is composed of serpentized ultramafic rock, and the scarp or cliff apparently marks a fault forming the contact between the ultramafic rocks and schists of the Rattling Brook Group. The rocks that compose the cliff are fairly resistant to weathering but have large scale jointing, resulting in the weathering of blocks and boulders from 1 to 2 m in diameter. Close to the cliff edge strong jointing parallel to the cliff (oriented NE-SW) dips at steep angles to the southeast, resulting in overhanging faces in some areas.
The rock that struck the house is shaped like a rounded disc, with dimensions of approximately 2 metres by 2 metres by 1.5 metres. The volume of rock is thus 6 cubic metres; using a specific gravity of 2.5, this gives an approximate mass of 15 tonnes.
The origin of the boulder, and the path it took to the house is clearly visible. The release point is from approximately 15-20 metres above the house, about two-thirds of the way up the slope in a well treed area. The slope at the point of release is at least 60 degrees. The rock on release fell nearly vertically for 2-3 m before impacting the slope where the angle lessens to 20 to 30 degrees. From this point the boulder appears to have rolled downslope. 8 m down slope from the first impact point the boulder clearly struck two trees and another large boulder, deflecting its path from directly down the slope, and towards the Philpott house. It rolled a further 10 metres on the slope- at this point approximately only 12 degrees before impacting the corner of the Philpott house.
Inspection of the area of the release shows that a second boulder, approximately 1 m in diameter also fell at this time but was held up by trees and remains on the slope. Other rock fragments with a fresh appearance are found elsewhere on the slope, likely broken off the largest boulder.