MADISON - The medical helicopter that crashed in Wisconsin did not have two pieces of safety technology the National Transportation Safety Board has recommended to prevent crashes, company officials said Monday. Ground level raw video from WKBT. Click on the Related Content link. Mike Allen, senior vice president at Denver-based Air Methods, said the helicopter was not equipped with a computerized voice system to warn of approaching terrain or night vision goggles for the pilot. His company leased the helicopter to the University of Wisconsin Hospital for its Med Flight program that crashed Saturday night after dropping off a patient at a La Crosse hospital. There were no survivors in the crash that killed a surgeon, nurse and pilot. An NTSB investigator was on the scene in western Wisconsin Monday to begin determining the cause of the crash. But officials have said the helicopter appeared to strike a hill or trees shortly after taking off from the La Crosse airport on a return flight to Madison. The helicopter had stopped at the airport to refuel. The crash that killed surgeon Darren Bean, nurse Mark Coyne and pilot Steve Lipperer devastated the Madison medical community. The university system's other helicopter remained grounded Monday, and Med Flight program manager Mark Hanson said regional hospitals would handle calls for service until the staff was emotionally ready to resume flights. The hospital started a fund at the university's foundation for donations that poured in, along with well wishes from around the world, hospital spokeswoman Toni Morrissey said. Hospital workers observed a moment of silence to reflect on the loss Monday afternoon and were considering how to honor their colleagues permanently. "We've lost three brothers," Hanson said. "Young promising professionals that had a lot to offer, that still have a lot to offer. It's very hard." Bean, 37, had been a Med Flight physician for the hospital system since 2002. Coyne, 53, was a 22-year veteran of the program. Lipperer, 39, worked for Air Methods and had been a contract employee for the hospital system since 2000. As the mourning continued, Air Methods officials found themselves facing questions about why the new American Eurocopter EC135 that crashed did not have the most modern safety equipment. The NTSB recommended night vision goggles and the computerized warning system in a 2006 report that suggested many fatal EMS flights could be prevented. The report came after the agency noted an increasing number of crashes involving medical helicopters and planes. Federal regulators have not required the use of either technology but encouraged companies to voluntarily install them. But a shortage of night vision goggles for nonmilitary use and other technical challenges have slowed installation, industry officials said Monday. Allen said his company was in the process of retrofitting its 348 helicopters with both pieces of equipment by the end of 2011. About 40 percent of its craft already have night vision goggles, while 6 percent have the so-called Terrain Awareness and Warning Systems, he said. There's a long wait for the equipment and then it takes time to train crews, Air Methods CEO Aaron Todd said at an afternoon news conference. He said he couldn't say whether the technology, which costs about $100,000 to install on each craft, could have prevented the crash. The company said that model aircraft had only crashed once before in 2005 in Washington D.C., killing two. "It's been a very safe aircraft for us," Allen said. NTSB spokesman Keith Holloway said it was too early to say what caused the crash, which was the first since the university hospital system started operating the air flight program in 1985. He said his agency will document the wreckage, look for anomalies in the craft, and review the maintenance records and the pilot's history as part of its investigation. Studies have shown that flight into hills and other terrain is a common factor in helicopter EMS accidents, particularly during takeoff and landing. More accidents also happen at night and when patients are not on board, just like Saturday night's flight, studies show. The NTSB said the warning system would improve safety by warning pilots 25 seconds or more before potential impact with terrain. In 17 of 55 accidents analyzed, the system might have prevented the crash, the report said. Similarly, night vision goggles enhance pilots' ability to see and avoid obstructions such as wires, which are commonly hit, the NTSB said. In 13 of the 55 cases, goggles might have helped pilots prevent accidents, the board said. Goggles should be used only when pilots are flying visually and not using instruments, the NTSB said. Lipperer was flying visually, which industry officials said was a common practice in good weather. Weather was not a problem when Lipperer took off, Allen said. The company had equipment on the helicopter to track it by satellite from a control center in Denver. Workers there received data showing the flight took off but did not receive an expected update three minutes later, Allen said. "At that point we suspected there may be problems and began trying to contact the aircraft," he said. (Copyright 2008 by The Associated Press. All Rights Reserved.)