WENTZVILLE, Mo. (AP) _ A wooden deck at a campground crowded with Grateful Dead fans collapsed in the rain, injuring more than 100 people.

Some of the injured were on the second-story deck and others were underneath it when it collapsed around midnight Wednesday, police said.

Estimates of the total number of injured ranged from 100 to 150. At least 87 people were treated at hospitals. Of those, three were in critical condition this morning and six were in serious condition.

``People were just hiding from the rain. There were just too many people,'' said Sarah Zimmerman of suburban Florissant. ``I heard a loud crash and then felt the weight of the wood falling on me.'' She escaped with cuts and bruises.

Earlier Wednesday, about 20,000 people attended the sold-out concert at Riverport Amphitheatre in suburban St. Louis. The band was scheduled to perform again tonight.

Dennis McNally, publicist for the band, said late this morning that he wasn't sure if the band was yet aware of the accident at the campground.

``It amounts to a tragic accident happening to members of your family,'' he said. ``In our hearts we'll play tonight's show for them.''

About 4,000 fans _ known as ``Deadheads'' _ have taken up residence at the Pinewoods campground about 40 miles west of St. Louis. Many fans follow the band on its tours around the country.

The roof over the deck fell on those standing on it, and the whole structure then collapsed on top of other people who were below the deck. Police said the structure, about 8 feet wide and 30 feet long, was attached to a pavilion at the campground.

``A group went underneath and a group was on top dancing in the rain or something,'' said Sgt. Jim Kaimann of the St. Charles County Sheriff's Department. ``When they were dancing, the pavilion fell down on the people underneath.'' Investigators this morning were trying to determine why, he said.

Martin Limpert, spokesman for the St. Charles County Ambulance District, said the serious injuries included a broken neck and a severe head injury. There were also some broken arms and legs, he said. Some of the less severely hurt were taken to hospitals by school bus.

At sunrise today, the American flag at the lodge had been lowered to half-staff. Some of the Deadheads carried flowers and burned incense. Signs around the camp proclaim ``Wish them well'' and ``We will survive.''

A large crowd of campers milled around the fallen deck, where hats, liquor bottles and shoes were strewn about.

Wednesday's accident was not the first misfortune to befall the band's followers this week.

Two fans were found dead at the campground Tuesday night and Wednesday from what may have been drug overdoses.

On Sunday, a Grateful Dead concert in Indianapolis was canceled after fans without tickets stormed a fence and threw rocks and bottles at police. About 220 officers in riot gear tried to quell the crowd with tear gas, pepper spray and police dogs.

And on June 25, three people were hospitalized in Washington, D.C., after being struck by lightning while waiting outside RFK Stadium for a Grateful Dead-Bob Dylan concert to begin.