Plane returns to O'Hare with sick passengers

CHICAGO (WLS) -- A medical emergency forced United Flight 1218 to return O'Hare International Airport shortly after it took off.

Ambulances met the plane at the gate upon its return Tuesday morning. Officials said the plane had pressurization problems after taking off at 8:41 a.m. United Flight 1218 returned to O'Hare and landed safely at 9:48 a.m.

Officials said three or four passengers reported feeling "discomfort." All 174 passengers and seven crew members were checked out by paramedics, according to the Chicago Fire Department. No one was transported to local hospitals.

Flight 1218 was headed to Denver. Mechanics are currently checking out the plane.