At least four people were killed and 40 people were injured in a stage collapse at the Indiana State Fair during a severe thunderstorm on Saturday night.Indiana State Police confirmed the fatalities and said the injuries to some victims are so severe that the death toll could rise. Watch: View Slideshow: | Information about the people who died wasn't immediately released. ISP 1st Sgt. Dave Bursten said that the Marion County Coroner's Office had confirmed the identities of two of the people who were killed by early Sunday morning.The number of injured could also increase, as authorities don't have a handle on how many people drove themselves to hospitals or were taken there by means other than an ambulance.A news conference at the fairgrounds was scheduled for 9:45 a.m. Gov. Mitch Daniels, Mayor Greg Ballard, state police and state fair officials are expected to address the media. 6News and TheIndyChannel.com plan to carry the news conference live.The collapse happened about 8:50 p.m. as Sugarland, a country music act, was preparing to perform on the fair's main stage.The National Weather Service said winds estimated at 60 to 70 mph buffeted the stage ahead of a line of severe thunderstorms. A severe thunderstorm warning had been issued for Marion County before the collapse."What hit really wasn't a storm. It was a significant gust of wind," Bursten said.David Lindquist, a reporter for the Indianapolis Star who was there to cover the concert, told 6News that an announcement was made that weather was moving in about two minutes before the winds kicked up, but those in front of the stage had little time to get out of the weather, if they wanted to do so. Watch: "There is an evacuation plan that is prepared. There were preparations in progress in anticipation of a severe storm arriving around 9:15," Bursten said. "Personnel were being put in place for an evacuation if that were deemed necessary."An on-site emergency center was set up at the fairgrounds immediately after the collapse. Other people at the concert converged on the collapsed stage in the immediate aftermath, trying to pull the injured from beneath the mangled wreckage."It's gratifying to know that people at a moment's notice will jump in to help others," Bursten said."After the stage fell, it was complete chaos. Everyone had froze," said Jason Scofield, who was at the concert. "There was hundreds of people trying to lift the front of the stage up."People ran to escape the collapse, but they tripped over each other as the stage came down, another witness told 6News."It was very scary, but I'm very fortunate I escaped with minor injuries," a 14-year-old victim said. "There was people underneath the stage trying to get out. The stage hit me. It was like a scene from a movie. It just happened so fast."Indiana Task Force One was called in to search the debris, along with several K-9 units. The K-9 units were called back about 11:30 p.m., as the search beneath the stage was completed.Most patients were taken to Wishard Memorial Hospital and Methodist Hospital, both equipped with trauma facilities. Hospitals brought in extra personnel to handle an influx of patients.Other patients were taken by ambulance to various hospitals in and around Indianapolis, and some were driven to hospitals. Several children were among those injured, and at least three of them were taken to Riley Hospital for Children.The injuries run the gamut from broken bones to head injuries and severe bruises.The Indiana State Fair canceled events for Sunday and planned to reopen on Monday with a special ceremony remembering those who died and were hurt. It was not immediately known what will happen with concerts scheduled in the coming days.Lt. Gov. Becky Skillman, who also serves as the state's secretary of agriculture, expressed her condolences in a statement Sunday morning."Our thoughts, prayers and assistance go out to the families impacted by the tragedy. We continue to be grateful for the performance of our first responders and the instant reflex of Hoosiers helping Hoosiers," she said.Officials asked anyone worried about a loved one they haven't heard from after the stage collapse to contact the American Red Cross, which opened its headquarters on East 10th Street in Indianapolis. People trying to get in touch with loved ones can call the Red Cross at 317-684-4305. The organization said it had a list of 33 injured people as of 2:45 a.m. and was working to add others who were hurt to the list.Mayor Greg Ballard said he's pleased at the response from emergency responders. A command center had been set up at the fairgrounds this year."All the units are operating well together," Ballard said. "Everything is very coordinated to respond to this event."Officials urged people who were at the concert and weren't injured to update their social media accounts, such as Facebook and Twitter, to cut down on calls to authorities from concerned friends and loved ones.Sugarland posted this message on the band's Facebook wall:"You may see on the news that our stage collapsed tonight. We are all right. We are praying for our fans, and for the people of Indianapolis," the post read. "We hope you will join us. They need your strength."Sara Bareilles, the opening act at the concert at the fairgrounds Saturday night, posted on Twitter, "I'm speechless and feel so helpless. Please send love and prayers to Indianapolis tonight. My heart aches for the lives lost #indyiloveu."Train, a rock band set to perform with Maroon 5 at the fairgrounds Thursday, posted condolences on its Twitter page: "Indianapolis, we are so sorry that you are suffering right now. We are sending all our love and good wishes. Be there soon. Hoping to help."ISP and Marion County authorities will lead an investigation of what led to the accident. Watch 6News and refresh this page for updates.