Pilot Daniel Moore seriously injured, 3 others including infant sustain minor injuries after helicopter crashes on Burmont Road in Drexel Hill, Pennsylvania

While no official cause has been determined, Rayner said at an earlier briefing said the evidence points to this being an accident.

Officials say the crash was a miracle landing because the area in which the medical helicopter crashed is a heavily trafficked area and no one outside of the chopper was injured.

Brian Rayner, senior safety investigator with the National Transportation Safety Board, told reporters Wednesday he was grateful that the occupants were relatively unhurt in the 1 p.m. Tuesday crash.

“My main concern right now is the 2-month-old child. I need an ambulance here right away,” the nurse told a dispatcher.

Flight data shows the EC135 helicopter was heading in a “laser-straight course line” at a steady speed and altitude until it reached the Drexel Hill area of Upper Darby Township, where witness and video evidence “describes the helicopter maneuvering erratically” before it crashed in front of a church Tuesday afternoon, National Transportation Safety Board investigator Brian Rayner said.

The medic told investigators he and the nurse were out of their seats attending to the infant when they heard a loud "bang."