Baltimore Fire crews are investigating a 13-car freight train derailment inside the Howard Street Tunnel Monday morning.

Twelve derailed train cars were empty. One car was filled with a "possible flammable liquid" later identified as acetone, used in nail polish remover, according to fire officials. No hazardous materials were released during the incident.

Firefighters said there's no danger to the public. There were no punctures or leaks to the affected railcar and no poisonous gases or substances released, officials said. No fires or injuries were reported.

Investigators are looking into the cause of the derailment, yet officials aren't ruling out foul play.

The train derailed at 5:45 a.m. and closed several intersections near Mount Royal Avenue and Howard Street.

Motorists are advised to avoid Mount Royal Avenue between North Avenue and Charles Street.

Huge @BaltimoreFire response to reported train derailment in Howard Tunnel. No visible smoke or fire. @ABC2NEWS pic.twitter.com/HwAZqsLe98 — Brendan McNamara (@BrendanABC2) June 13, 2016

In distance, you can see at least one tanker on its side inside tunnel. @ABC2NEWS pic.twitter.com/q2ZPEH525A — Brendan McNamara (@BrendanABC2) June 13, 2016

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