Months after a CSX train collided with a truck in Rosedale, triggering an explosion felt around the region, a crash that killed two in Baltimore last week again raised questions about the safety of the state's railroad crossings.

Nationally, Maryland has one of the lowest rates of fatal crashes between trains and vehicles at grade crossings.

But the crossing on Hollins Ferry Road near Paca Street — where a man and a woman were killed when their SUV was struck by a MARC train early Tuesday — is considered the state's second-most dangerous. U.S. officials say there's a 15 percent chance that a collision could occur there in a given year.

Morgan Fleet, 23, and Wayne Burnett Jr., 38, were killed; the train's passengers were unhurt.

Police are investigating the cause of Tuesday's crash, in which the crossing's gate was down when authorities arrived. Experts say nearly all collisions at gated crossings occur when a driver tries to beat a train.

It can cost millions to improve crossings by elevating them or adding longer gates and medians to keep drivers from entering while gates are down.

The Federal Railroad Administration ranks crossings by the likelihood that a crash will happen in any given year, using a formula that includes a history of crashes, train speed and the average daily number of cars.

The ungated crossing in Rosedale, where the crash in May derailed the train leading to the explosion, is considered the state's 16th-most unsafe crossing, with about a 4.7 percent chance of a collision in any year.