Warnings preceded fatal New Hampshire circus tent collapse

LANCASTER, N.H. -- Safety officials in northern New Hampshire worked through the night investigating the collapse of a circus tent during a severe storm that killed two spectators and injured at least 22 other people.

Authorities were looking at how the tent was put up at the Lancaster Fairgrounds, about 90 miles north of the capital of Concord. They also were talking to survivors and witnesses.

Fire Marshal William Degnan said it was the first time his agency had investigated a tent collapse.

The storm, packing 60 mile-an-hour gusts, hail and much lightning, blew through around 5:30 p.m. Monday, just as the first of two scheduled shows was beginning.

Dozens of emergency crews from surrounding towns rushed to the scene, reports CBS News correspondent Vladimir Duthiers.

Degnan said about 100 people were inside the tent at the time, and a man and a girl died. Their names were not released. The injured were taken to four regional hospitals. Their conditions were not immediately known.

The circus operator, Sarasota, Fla.-based Walker International Events, did not return a call seeking comment late Monday. The circus was scheduled to head to Bradford, Vermont, for shows on Tuesday and Wednesday.

Walker International has nearly 50 more performances scheduled in the Northeast this summer, Duthiers notes.

CBS Boston meteorologist Eric Fisher said the National Weather Service issued a severe thunderstorm warning for the area about 20 minutes before the storm swept through. So, he said, there was ample time to get people to safety.

Degnan couldn't immediately say if the spectators were aware of the storm's strength.

Spectator Brandon Isham told CBS Portland, Maine affiliate WGME-TV his four-year-old son was hit in the head by a pole but is OK. He said when the downpour began, the tent flaps were open, not tied down, and rain was coming in as the flaps "started going crazy." Then, "next thing you know, the wind picked up, and took the tent with it."

The collapse comes a day after one man died and more than a dozen were injured when a tent where people had sought shelter during a brief storm blew off its moorings and fell on some of the crowd at a festival in a Chicago suburb. The annual celebration known as the Prairie Fest had attracted about 5,000 people when the tent collapsed. The family of the man who lost his life is filing a lawsuit, according to the Chicago Tribune.

The popular Lollapalooza music festival in Chicago's Grant Park briefly shut down Sunday afternoon due to the weather, then resumed less than an hour later. Organizers ended the final day of the festival 30 minutes early Sunday night when another storm hit the area.