As recounted in this article, in 1914 "one of the most powerful wireless telegraphic and telephonic stations in the world" had recently gone into operation at Laeken, near the Belgian capital of Brussels. The station was constructed under the direction of Rudolf Goldschmidt, at that time a professor at the University of Brussels. This station featured a Goldschmidt alternator-transmitter, and was powerful enough to transmit directly to the Congo, a Belgian colony in central Africa. But with the outbreak of World War One in August, 1914, just a few months after the station had gone into operation, the Belgians were forced to completely destroy the alternator-transmitter, plus blow up the extensive antenna system, in order to keep it from falling into German hands.

Radio Amateur News, November, 1919, page 220:

Destruction  of  the  Brussels  Radio  Station  in  1914

By  An  Eyewitness


IN the neighborhood of Brussels, upon a plot of ground given by King Albert, Mr. Robert Goldschmidt had erected one of the most powerful wireless telegraphic and telephonic stations in the world. This station was constructed so that direct wireless communication might be held between Brussels and Boma, the capital of the Congo State, a distance of about 4,000 miles. After trials extending over two years, Mr. Robert Goldschmidt succeeded in establishing communication with Boma three or four months before the declaration of war.
    Current was supplied by a high-frequency alternator driven by a motor of 400 horse-power, the current for which was supplied by an adjoining local supply at 6,000 volts. The maximum wave length was about 10,000 meters. The antenna consisted of 77 wires supported by eight steel masts of 7 square meters in cross-section placed in two parallel rows. The height of the two masts nearest to the station was 630 feet and that of the remaining six was 300 feet. All the masts were stayed with numerous steel cables. In the month of August, 1914, the foundations of a ninth mast of the same type as the others was commenced. This mast would have been square in section, the sides being 18 feet long and 1,000 feet in height, and arrangements had been made for an electric lift to reach the top. It was to be placed between the other masts to raise the antenna, and thus increase the radius of action of the installation.
    On Wednesday, August 19, of the year 1914, the most contradictory rumors reached Brussels. Some folks affirmed that the Germans were at Louvain and would not stay to enter the capital. Others said that the town was protected by a ring of troops. Nevertheless, the hurried departure of Queen Elisabeth appeared to support the views of the pessimists. Another event more unexpected and more convincing succeeded in persuading all that the enemy was at hand.
destroyed site
    About one o'clock in the afternoon a violent explosion was heard in the direction of the wireless station at Laeken, near Brussels. By chance I was close by. At first I thought that the bridge had been blown up, when suddenly I was astounded to see one of the wireless masts bend over and fall to the ground. I had scarcely recovered from my surprise when another explosion occurred, more violent than the first, and a second mast fell. "They are blowing up the station; the Germans must be near," I said to myself. I tried to get nearer, but at 200 meters from the station I was stopt by a cordon of town guards. By making a detour I was able to skirt the station, and was then only separated from it by the canal of Willebroeck.
    I waited for some moments, and then the characteristic throbbing of a Taube aeroplane made me lift my eyes. It came slowly toward me, gradually descending until I could quite clearly see the black cross painted on its wings. It flew over the station, encircling it twice, and was starting in the direction of Louvain when suddenly a shot was fired near me; others followed and continued unceasingly for some minutes. The Taube aeroplane, finding itself a target, turned slowly and disappeared. A group of Belgian military engineers ran to the other side of the canal and called out to me: "Look out! Run for your life!" Without knowing why, I ran back some yards. A third explosion occurred, and a third mast fell to the ground. The soldiers returned, and one after the other the masts fell. The soldiers had cut the cables on one side so that the masts bent toward the other side; then, having mined the foundation; they fired the fuse and ran back as quickly as possible, while the light metal framework slowly crumpled up in the midst of volumes of thick, black smoke.
    In one case a mast was prevented from falling by the antenna of a neighboring mast. In another case the first explosion only shook the mast, and the blasting had to be repeated once or twice until the mast was utterly destroyed. At about half-past three the antennae were entirely destroyed, but the transmitting and receiving station was still intact. This station was situated in a tunnel under the Vilvorde Road, between the Willebroeck Canal and the ground where the masts had stood.
    It was only possible to carry away some of the light instruments; the remainder had to be destroyed. The most delicate parts were broken up with hammers, and to complete the destruction the station was blown up with dynamite. The explosion was so violent that part of the granite parapet was broken and a large crack opened in the roof of the tunnel. Finally, so that even the ruins could not be put to any possible use, the station was filled with straw and hay and set on fire. A dense smoke rose from the tunnel. It was seen rising over the canal until the evening, and the last bursts of flame were not extinguished when a detachment of the enemy's cavalry appeared on the scene.
    We heard afterwards that the Germans had hoped to seize the wireless station, which would have put them into communication with the most distant points of the theater of war. Orders had been given to a troop of cavalry to advance by forced marches to prevent its destruction, but the Belgian authorities, warned of this move, were able to forestall them. The German plans were frustrated, but the defeat cost Mr. Robert Goldschmidt not only an enormous sum of money, but also the patient research and labor of three years.