HOUSTON - Two people were killed and a third critically injured as a medical helicopter crashed on Friday morning in the US state of Oklahoma, local media reported.

The EagleMed helicopter crashed around 5:45 a.m. between two buildings in Oklahoma City on its way back from a hospital to its home base in Watonga, Oklahoma, according to a report by CBS affiliate KWTV-TV.

Residents nearby heard a loud explosion and immediately called 911.

Eyewitnesses reportedly saw smoke and flames just after the chopper went down.

The helicopter did not hit any building or hurt anyone on the ground, according to the report.

Two of the three crew members on board were killed in the crash, and the other one was pulled by rescuers from the wreckage just before an explosion. The injured was hospitalized and remains in critical condition.

Investigators from the Federal Aviation Administration and the National Transportation Safety Board have arrived at the site and are inspecting the wreckage, the report added.

This is the second fatal EagleMed crash within three years. In July 2010, an EagleMed helicopter crashed in Kingfisher County, Oklahoma, killing the pilot and a flight nurse. Another crew member survived that crash.