SALT LAKE CITY (AP) — The mere report of a man acting suspiciously was enough for authorities searching for 14-year-old Elizabeth Smart to block off a heavily wooded canyon and search through the night.

About 1,200 volunteers on Thursday spread out across the city to try and find the girl taken at gunpoint in her pajamas from her Federal Heights home.

One of the volunteers reported seeing a man acting suspiciously at the top of Emigration Canyon on Thursday evening, setting off the search, which continued there Friday morning.

The girl's father, Ed Smart, was hospitalized Friday morning after collapsing from exhaustion. He had slept little in the more than 48 hours since his daughter's disappearance. The family did not say which hospital he was in.

The volunteer searcher in Emigration Canyon told Salt Lake City television station KTVX that he saw a man there wearing a white hat and white shirt, which fit the description of the kidnapper's clothing.

He said it appeared the man might be trying to wipe out footprints. He said he followed the man, lost sight of him and then heard gunshots. He didn't see the man again.

Salt Lake County sheriff's officers arrived within 20 minutes and closed off the canyon, said city police spokesman Fred Louis. A helicopter with infrared equipment and deputies searched through the night and into the morning.

There is at least one transient who lives in the rugged area of forest and sagebrush, sheriff's spokeswoman Peggy Faulkner said Friday. That may have been the man the searcher saw.

Police say if they find the transient they will question him to see if he fits the description of the abductor, but he is not considered a suspect.

Earlier, police had said that despite more than 1,000 tips, with calls arriving at police headquarters about one per minute, they were no closer to finding the girl.

The reward was initially $10,000, but donations from the community boosted the fund to $250,000.

Pictures of the missing girl were posted throughout the city and on the Internet and people started wearing light-blue ribbons -- Elizabeth's favorite color -- and hanging them from trees and car antennas.

Police said that on Wednesday between 1 and 2 a.m., an intruder forced open a window at Elizabeth's home and went into the bedroom where the teen-ager and her 9-year-old sister slept. Police said the gunman warned the younger girl her sister would be harmed if she told anyone.

Because of the gunman's threat, the younger girl waited several hours before alerting her parents, police said.

The kidnapper did not call Elizabeth by name and he did not appear to know his way around the house, the sister told police. No neighbors reported anything suspicious.