FREMONT, Calif. -- Seventeen purebred puppies were discovered missing Thursday morning from a Fremont pet store, puzzling police and precipitating a crippling fall by an employee searching for clues on the roof, a police sergeant said.

The employee in his late 20s fell from a Puppy Love Boutique overhang about 15 feet tall, through a skylight and onto the cement in front of the store, Fremont police Sgt. Jeff Swadener said. The fall sent him to the hospital with major head injuries around 10 a.m., while police were on site filing the robbery report.

Employees opened the shop around 8:30 a.m. at 5174 Mowry Ave. and found their high-end puppies missing, in addition to the puppies' paperwork and other supplies, but they could not figure out how the robber got inside, Swadener said.

The missing canines included purebred Dalmatians, Saint Bernards, Pekinese poodles and schnauzers, among other breeds. They ranged from 9 to 13 weeks old and could have sold for $650 to $1,100 each. The robber or robbers "knew what they were looking for because they left common and less expensive puppies," Swadener said.

While police were inside the store, the employee saw some tiles in the ceiling that were possibly displaced. He decided to use a ladder to get onto the roof and try and find out if whoever stole the puppies used the roof for an entrance.

Swadener did not know what caused the man to fall.

He said police were investigating many puppy thief possibilities, such as construction workers who have access to many stores in the strip mall, past employees and local activist groups who have protested the store in the past.