Forensic Quiz

Forensic engineering is like putting together a jigsaw puzzle, with one major difference.  When working on a jigsaw puzzle you know ahead of time what the "answer" is, and you arrange the pieces to create the picture on the cover of the box.  With forensic engineering you start with pieces, but not only do you have to determine what the picture is, but also which pieces even belong to the puzzle.

Take our forensic quiz below and get a taste of forensic engineering.  The scenarios described are from the forensic files at Harms Engineering, Inc. (HEI).  First read the description of each "accident", then choose which solution seems most likely to be the correct one.  At the end click "How did I do?" and see what your IQ (Investigation Quotient) is.

Test your knowledge with some case studies!

Toaster Fire
It was reported that a teenager put some bread in the toaster for lunch, then went to her boyfriend's house next door.  After being there for awhile, a neighbor noticed smoke coming from the teen's home.  Rushing back to the home, the teen discovered the kitchen engulfed in flames, which were determined by the fire fighters to have started in the vicinity of the toaster.  What caused the fire?
Toast in the toaster burned, setting the cupboard above on fire
Napkin fell on the toaster while it was hot
Someone poured accelerant on kitchen counter, then lit a match
Fire cracker was tossed into the toaster

Exploding Handrail
A maintenance worker was drilling through a handrail at a hydro dam in order to install an electrical conduit, when there was a sudden explosion in the vicinity of the handrail which burned his face, clothes, and arms.  He was rushed to Harborview Hospital because of the severity of the burns.  HEI was called in to determine the cause of the explosion. Was it from:
Gas from decaying animal trapped in the pipe
Hydrogen gas formed from galvanizing during the pipe manufacturing process
High voltage line touched by maintenance worker
Explosive planted by terrorist

White Interior of Home Mysteriously Turns Gray
A new home was decorated entirely in white.  White tile, white carpets, white furniture, white paint.  One day the owners noticed unexpected footprints on the kitchen floor.  Surveying the home, they discovered that every surface had a fine gray film. What caused this film?
There had been a dust storm, and all windows were open
Smoke from the fireplace circulated via the HVAC system
The homeowners don't like housework and chose an impractical color scheme
Smoke from an oil lamp with a long wick circulated via the HVAC system

Veterinary Office Fire
After a day at the office, the owner of a veterinary clinic went home, only to be awakened in the middle of the night by emergency personnel informing them of a fire that had started in the kitchenette of the clinic.  The fire was serious, causing the death of several animals.  Upon examination, the source of the fire was isolated to an area around a small hot pot.  How did the pot start the fire?
Hot pot's plastic lid melted, dropped into the empty pot and burst into flames
There was a short in the electrical cord
Hot pot was left "on", heating a nearby towel to its kindling temperature
An animal escaped from its cage, entered the kitchen and accidentally tripped the switch

Midnight Landslide
A county road was built on the side of a hill, winding through a woody residential area.  One night the residents were awakened by the sound of rushing water and moving earth.  Upon investigation it was discovered that the upper road had collapsed and slid down to the road below.  The source of the water was determined to be a broken irrigation pipe that had previously been buried.  What caused the irrigation pipe to fail and the road to collapse?
Corroded irrigation pipe
One of the joints on the pipe failed
Unconsolidated backfill shifted, breaking the buried irrigation pipe
Rusty old pipe had reached the end of its useful life

Irrigation Pipe Causes Fatility
An elderly man was working in his backyard when suddenly there was an explosion from beneath the ground, causing a high pressure spray of water accompanied by shards of PVC pipe.  One of the shards struck the man in the head and killed him. The water came from a 6" underground irrigation line. What caused this accident?
Water pressure spike
No thrust block at elbow fitting
Failed PVC pipe joint
Inferior (weak) PVC material