TAMPA, Fla. (WFLA) — Three people were killed Sunday in a massive pileup in heavy fog on Interstate 75 in northern Florida, the Alachua Chronicle reported.

According to the report, the Florida Highway Patrol said 21 vehicles were involved in a crash at about 12:40 a.m. Sunday near mile marker 414 in Columbia County.

The crash closed the northbound lanes of the roadway for nearly 12 hours.

There is still no word on what led to the crash or who was killed. The area was under a fog alert at the time and visibility was low, according to the Chronicle.

As of Monday morning, the crash remains under investigation.