BALTIMORE (WJZ) -- Units from Baltimore County and Howard County are responding to a "serious crash" involving a tractor trailer and another vehicle on a stretch of eastbound of I-70, the Baltimore County Fire Department said.

As of 6:30 p.m., eastbound I-70 is open, while the westbound lanes are closed.

All eastbound lanes were previously blocked between exit 87 and exit 91, the fire department said.

Maryland State Police investigators believe a tractor trailer rear-ended an Acura, which rear-ended a Lexus. All three drivers were hospitalized, but their conditions are unknown.

Police said impaired driving is not believed to be a factor in the crash.

WJZ's Vic Carter reported traffic was backed up for at least 20 minutes.